possible tree locations

Mark,

these locations and specifics are subject to change based on location of utilities and water lines but at least these sketches suggest possibilities.

revised soil depths/plant height

Aaron,

Lisa will go over this with you along with questions/concerns we have.

changing colors

meeting Minutes 11.24.09

Call Participants: Mark, Aaron, Karla, Lisa

Time: 2-3pm PST

Summary of Discussion:

We discussed park area on east side and bus stop areas as a place for tree donations, mark had commented that the consulates are intrigued with the olive trees and contributing in that manner.

we are exploring opportunities for an allele or colonnade. We also discussed william the engineers concerns and comments. There is 46 sq/ ft available depth can be 6"-42"

Aaron and mark had several comments on soil depths.. ant to see more fluid and accentuate parapet walls and utilize radiuses. It has a map like quality and want to keep that yet soften a bit

Also looking at how this feels from the park and grove view on the southwest corner. Want to incorporate this feeling of being manmade, somewhat different and hi-contradictory soft, less defined different. Lighter and more ethereal is what Lisa added. We also discussed seasonality of the grasses and the changing of the garden.

Mark noted us to his comments on an earlier post….

"I see you've modified this page somewhat. I was looking to show my 11 year old son the image that was up yesterday with several plants bubbled out and lines connecting to where they would be planted. Now the bubble image only has a few plants.

I think his initial reaction to the garden renderings is important: "Whoa. Scary." My response was a little more measured, 'too furry,' and thus not as helpful. I'm leaning towards something that feels more managed.

Let's keep in mind an important part of what our Museum does. Granted, the core of our exhibits chronicle the worst of human action. But the fact of the Museum is also healing. We take the terrible material and we control it, frame it, give it a beginning, middle and end. In this way we create opportunities to move beyond it.

The garden should reflect this kind of framing. It thus needs to appear manicured. Or at least there should be a tension between the manicuring and the overgrowing that is resolved towards order, control, a sense wrong set right."

This is to be memorialized forever and protect artifacts, providing a smokescreen or protective barrier. The survivors have a desire to frame their memories, artifacts and items. They want to preserve them and keep them safe and protected to create a feeling of "it can't hurt me any more.."

Visitors are welcome to come and leave. It is a safe place to keep these as you can view them but you don't have to take them with you.Mark emphasized the beginning middle and end.. a healing.

"we don't heal when we wallow, we don't heal when we forget, we heal when we find a middle ground"

we want to frame it so we can have a life outside of trauma. There could be an analogy with the agaves. lisa and Karla will explore this more in depth. MArk liked rosette shape of the agave prynnii

Another item to be discussed is the parapet walls leading into concrete curbs surrounding the internal beds. A barrier is needed for maintenance and longevity.

Action items:

1. Aaron will speak with martin about adding a curb around areas 4, 11, and 12 that will separate the beds from the DG paths.

2. Aaron will coordinate with Roofscapes on Drainage

3. Lisa and Karla will provide a seasonal study, landscape layout with olive tree allee/colonnade , and a revised soil depth plan.

4. Lisa and Karla will research more accent plants to find the one that is a perfect fit.

5. Aaron and Lisa will collaborate on soil modeling

Note: Karla will be out of town until Dec 7th

RE: Charlie's comments

4. Barriers to flow: Many of the walls, unless modified, will provide barriers to water drainage. There are two possibilities: a) install these walls over high-strength sheet drains that will allow free flow of water under the length of these walls, or b) provide substantial scupper openings at all low points. We recommend building rectangular scuppers into the walls, each several inches high and a foot, or more, in length. We can work with the design team to determine how best to design and position scuppers.

Refer to detail attached (from #3). We had planned on providing weep holes at the bottoms of walls to allow drainage of water. // See comments above—we recommend large rectangular scuppers or, alternatively, casting the walls on top of sheet drain. Please provide a drawing showing the size and locations of weep holes so that we can submit these to our structural engineer. Please note that the engineer has already given us a max penetration through beams (of which we have a few we will need to drain through) of 2" diameter. // beams are a special case, since these must be cast in the initial pour and they are structural. You mentioned that circular penetrations are not as effective as rectangular. Please confirm your preference. // We definitely want rectangular openings. If a 2” clearance is dictated by the engineers, then we would suggest a series of 2”x8” or 2”x6” sleeves be placed through the beams before the pour (we suggest Certainteed Form-A-Drain for this purpose). Can you confirm this with your engineers? Also, we need to think about installing 2” diameter pipe sleeves through the beams (and walls) for electrical and irrigation lines. A preliminary layout for plumbing stub-ups, irrigation supply lines, and electrical conduit should be prepared before the slab and beams are cast. William Koh the structural engineer will need to know the the worst case scenario of the spacing between weep hole locations along the planter walls.

Plan 03-Beam Clarification

Please see the revised roof plan. Notice added item 14.

Planting Design

Clarifications

In regards to our conversation today, I wanted to clarify a couple of the things we discussed.

A) Because the plant palette is not yet finalized, the green roof profile is not yet finalized, however, the roofer only needs to install the waterproofing membrane. All other components can be considered part of the green roof profile and installed by the green roof installer. This will help to insure that the scope of the green roof is not broken up and accountability is easy to assess.
-No sheet drain needs to be provided by the roofer or membrane manufacturer (although it may be part of the green roof system depending on the ultimate build up.)
NEED CLARIFICATION-Roofscapes, Inc. is unclear if insulation is required in the build-up. We have discussed using insulation to meet elevation requirements but we are unclear as to whether it is otherwise required in the roofing build-up. Please clarify.

B) Roofscapes, Inc. provides a warranty for our green roofs, however this warranty is only offered if the green roof (all components above the waterproofing membrane) is installed by a trained and licensed Roofscapes, Inc, Network Contractor (much in the same way that roofers are certified to install particular membranes). Roofscapes, Inc. will be on site to supervise the installation as part of our Quality Assurance Program (see attached). If there is a contractor that is not in our Network, we would be happy to discuss the option of them joining our Network.

C) 3 membranes are being considered, EPro, Sarnafil, and American Hydrotech.
-The EPro and American Hydrotech products require an extra root barrier to be installed over the membrane. Please make it clear if the roofers intend to install this layer, what exactly the product is and how it will be installed. Roofscapes, Inc. recommends a minimum 30 mil polyethylene, polypropylene, or PVC, heat welded at the seams.
-The root barrier could be installed by either the green roof contractor or the roofer.
-EPro and American Hydrotech should confirm that they will honor their waterproofing warranties with the designed green roof on top of their membrane. Sarnafil and Roofcapes, Inc. have a national agreement to provide a comprehensive warranty covering the entire system including all components above the waterproofing.

D) EFVM testing is a leak detection method.
-The test can be used as a quality assurance measure (preceding green roof installation) to insure that the waterproofing is water tight and it can also be used to locate a leak if one occurs in the future.
-In order to use the test for quality assurance, nothing needs to be installed under any of the membranes as long as the membrane is in contact with the roof deck. If Sarnafil chooses to install their system over other components then a grounding screen should be installed directly below the membrane in order to use EFVM for quality control.
-When the test is conducted the technician will place a wire around the perimeter of the roof areas. Laying this wire is part of the cost of the test and does not need to be included in any contractor's scope.
-The root barriers that will be installed with the EPro and American Hydrotech systems could potentially interfere with the use of EFVM should it need to be used to locate a leak in the future.

E) The concrete walls WILL NOT be poured on top of a sheet drain, which means that rectangular scuppers will need to be installed in the walls in order to facilitate proper drainage between the different green roof areas.
NEED CLARIFICATION-Roofscapes, Inc. has not seen a roof plan that shows where the roof drains are actually placed on the roof. Please send us a plan or photos that show where these drains are actually located so that we can create a plan for where the scuppers need to be placed and how large they need to be.

F) Lisa and Karla are getting closer to finalizing the plant list. Once the plant list is understood we need to clarify exactly what the water burden will be for the irrigation system.

Please let me know if you have any questions.

Regards,

Nate Johnson

MEETING AGENDA

Time 900am PST

participants: Martin, Aaron, Charlie, Nate, Karla, Lisa

Call Number 218.339.2622

Access Code: 662677#

Agenda:

1. Formal introduction Martin, Aaron and Roofscapes with a quick overview of their function

2. Transparency:

who is at the table:

-waterproofing

-cover system

-components, media, irrigation plants

what are the requirements?

-cost

-schedule

-warranties

-collaboration, workability

3. Best practice, warranties, guarantees, upfront vs.long term costs, maintenance

4. ILD: testing and leak detection... this is critical!

5. misc items:

ground landscape

Aaron,

here are my questions for the ground level landscape along with a plan with notes for reference. Please respond to my questions and foward any updated plan you might have.

1. Please clarify areas, i.e. now that 13 is on the ground does that change the sf for area 1?
2 where are the areas A-F (F is all the beds around the monument?) on the ground?
3. We need to add a bed along the wall for vines? Can we make this 1' wide? 18" wide?
4. What are the new bed configurations around the monument?
5. can we add more turf around the monument because this is a heat sink and grass even though it is evil will mitigate heat island affect.
6. how does 8 transition to the ground to the east. Should our soil depth be 2' throughout? Can we plant trees there?
7. What is going on with the stairs and the slope transition to the park area?

8. Carina told us there were areas on the southwest side by the bus stop that needed our help with screening methane boxes and such. I remember 2 unsightly things that needed some shrubbing up. Are there any others?

EPRO drainboard etc.

Martin is meeting with Roofscape's rep or installer now as I write this entry. I have to clarify Charlie's communication which I told Martin...

On 10/30/09 I Charlie Miller spoke with David Polk at EPRO

His notes indicate:

1- They use a 15 mil root-barrier membrane. I asked for the root-barrier to be overlapped by 4 feet or hot-air welded. David agreed to this requirement.
2- EPRO has a drainage sheet product. They would like to use it (of course), but David said that they would not be dogmatic about.
3- I told David that Roofscapes, Inc. would allow EPRO to review and approve our green roof design.


For the record, Martin's number is 310-473-8490 at the office and 310-948-2730 for his cel.

charlie's comments

Our comments are as follows:

1. Slope stabilization: With the wall layout, the only viable approach to support the steep slopes would appear to be by suspending cellular confinement webs or high-strength geogrid from the top of the slopes. Since the pitched areas are transected by walls, this will mean that attachments will be required along at least 5 different wall segments and also at the structural bean on the far west of the project. These attachments could take the form of stainless steel anchors that are either cast into the walls or installed by drilling into the finished walls. In our opinion, the spacing between anchors should not be more than 18”. Once the thickness of the soil layers in planted zones 3, 4, and 5 are established, Roofscapes, Inc. can compute the static pull-out forces for the anchors. The height of the anchors above the slab will depend on the final design for the landscape. Moment forces associated with these anchors will have to be taken into account for the design of the walls.

This sounds like a good approach. Please provide drawings and specification that we can send to our structural engineer for review. //The first step is to determine the profile for the planted areas. This will establish the elevations for the bottom of the soil profiles.

2. Border edging: In transitions between decomposed granite and planted areas (associated with planted zones 1 and 10, some sort of structural edge will be needed to stabilize the decomposed granite walkways. While this could be custom fabricated stainless steel, we believe it would be considerably cheaper to cast curbs at these locations (green lines on the layout).

The planted zones you refer to are defined by planter walls, so those should not be an issue. // the planted areas that are inboard of the walls and adjacent to the walkways do not currently show walls or curbs (areas 1 and 10 on my attached diagram). However, your point does apply to defining zones 11,12, and 4 (in some areas) from the walkways. We were thinking if the material can be kept below grade so that it is a not visable, would a plastic fence be more cost affective.// If the edges will be invisible (below grade), either a plastic or aluminum edge can be used. These must be installed in conjunction with a reinforcing mesh to provide horizontal stability. Also, we assume that the decomposed granite walkways will be installed over a high strength sheet drain. The edge detail must promote flow under the edge and into the sheet drain. This is one of the details that we will prepare. Note: These edges could also be cast-in-place concrete.

3. Walkway transition: We would like to receive a definitive cross-section showing the transition between the decomposed walkway the planted zone 10. We believe that the most practical solution for this transition will be to install the decomposed granite (and curb) over a high-strength sheet drain. This will allow percolated rainfall and excess irrigation water to flow underneath the walkways. Effective uniform drainage of the planted zones is essential. Alternatively --- the walkways could be constructed as barriers to flow. In this case an efficient subsurface drainage network will be required to collect underflow and convey it to an area drain located within zone 10.

See detail attached. We have a drain board specified for the entire roof (1" ) and up the planter walls (3/8"). // As stated above, we presume that a 3/8” thick strength sheet drain will be installed UNDER the walkways. The transition of flow at walls will be tricky and will probably have to be handled in various ways. One solution at walls will be to install a 1” sheet drain UNDER segments of the walls before they are poured/shot. This is a simple, effective, and tested. However, as we have discussed, at some locations rectangular inserts may be placed through the walls, creating high-efficiency ‘scuppers.’ Transitioning runoff to the subsurface scuppers will take some design planning. Roofscapes, Inc. has agreed to develop proposals for these various drainage conditions. Note: We see no reason to place sheet drains up the face of walls.

4. Barriers to flow: Many of the walls, unless modified, will provide barriers to water drainage. There are two possibilities: a) install these walls over high-strength sheet drains that will allow free flow of water under the length of these walls, or b) provide substantial scupper openings at all low points. We recommend building rectangular scuppers into the walls, each several inches high and a foot, or more, in length. We can work with the design team to determine how best to design and position scuppers.

Refer to detail attached (from #3). We had planned on providing weep holes at the bottoms of walls to allow drainage of water. // See comments above—we recommend large rectangular scuppers or, alternatively, casting the walls on top of sheet drain. Please provide a drawing showing the size and locations of weep holes so that we can submit these to our structural engineer. Please note that the engineer has already given us a max penetration through beams (of which we have a few we will need to drain through) of 2" diameter. // beams are a special case, since these must be cast in the initial pour and they are structural. You mentioned that circular penetrations are not as effective as rectangular. Please confirm your preference. // We definitely want rectangular openings. If a 2” clearance is dictated by the engineers, then we would suggest a series of 2”x8” or 2”x6” sleeves be placed through the beams before the pour (we suggest Certainteed Form-A-Drain for this purpose). Can you confirm this with your engineers? Also, we need to think about installing 2” diameter pipe sleeves through the beams (and walls) for electrical and irrigation lines. A preliminary layout for plumbing stub-ups, irrigation supply lines, and electrical conduit should be prepared before the slab and beams are cast.

5. Flow patterns: Based on Drawing A2.1e and P-2, it appears like the rows of drains located on the north and south perimeters of the building as well as the row immediately south of the ramp will serve only the narrow planters in these areas. In particular it appears like the southern row cannot be effective in capturing runoff from the adjacent and up-gradient planted areas and walkways. Is there a plan to connect the areas north of the high parapet wall with these drains? We can be of assistance in suggesting some solutions.

I believe the row of perf pipe on the north is no longer necessary and is an artifact from an older design. The intention of the southern row, at the perimeter of the building, was to help carry water in that narrow planter towards the west. Please advise if you believe this to be true. I am not sure that the row south of the pedestrian ramp helps either; please advise. //Where will the roof drains and channel drains be located. Is this flexible? The drainage plan will be based delivering water efficiently to the roof drains. Who is in the lead on this?

6. Waterproofing flashings: We understand that most, or all, of the walls will be constructed using shot-crete. Will this concrete be hydrophobic? We are concerned that if this concrete can absorb water, it will become necessary to flash the walls at least 6 inches above the soil layer. This will have aesthetic and cost implications. There are many possible solutions for flashing the walls. We would be happy to discuss these with the team.

Our shotcrete walls are all 5000 psi concrete. Given that and the attached waterproofing detail, the flashing is a secondary measure. Will we have plantings that can cover the flashing if it is 6" above the soil? Can this be reduced at all? Please advise. // I do not have sufficient information to conclude how the waterproofing flashing should be installed. If the waterproofing contractor will certify the deck as watertight, even at re-bar dowels, then wall flashings would appear to be completely unnecessary. What sort of guaranty is the waterproofing installer providing? The nightmare scenario, if there is one, would appear to be moisture absorbed into the shotcrete walls, migrating to the rebar dowels, rusting the dowels and compromising the waterproof slab. I have no idea what design precautions have been made to mitigate against this possibility. We know of other jobs (Sika Sarnafl) where walls cast on top of waterproofing required no wall flashings. If there is any uncertainty about this, then I recommend that the flashing be extended up the wall and 6 inches higher than the top of soil.

7. Irrigation: Unless 2” diameter sleeves are installed across and under the various walls, curbs, and walkways, stub-ups for irrigation will be needed in every planted zone. Also, the irrigation valves and controls can be either centralized inside the building (e.g., in a closet or utility space) or they can be placed on the roof. The downside of placing them on the roof will be that each irrigation zone will require its own valve chamber (typically 8”-12” high, 15” wide and 24” long. These will be visible.

2" diameter sleeves are being provided under the planter walls and walkways. Irrigation valves and controls will not be inside the building but in the planter areas. How many zones do you calculate we will need? My understanding is that these boxes will be flush with grade- lets work together to be strategic about where these are placed so that they are not in highly visible locations. // The boxes can go anywhere. The number of zones will depend on the planting plan, and the desire (if any) for flexibility in changing the plantings in the future.

RE: adequate drainage in area #9 and #13

Karla,

in area 13, we would like to plant a small tree and grasses. Carina and Martin told us there was an adjustment that should be made to the proposed those "planter" walls to accommodate adequate drainage. I think the change was from a slab at the bottom to a spread footer. I think we should also make sure the same thing is happening in area 9.

The structural engineer is requesting the max. weight and growth of the proposed small tree in area 13. With this information we can design this planter with adequate drainage. We are also looking into area #9.

RE: Roofscape Question #2

the same condition exists at the transition from the entry concrete to the pathway by area 3. Carina had an idea but I can't quite remember the details. Considering the slope, this will be a constant maintenance issue with decomposed granite spilling onto the concrete.

I think maintenance will be to a small degree an issue at this particular location. We are working on a detail with the contractor to minimize maintenance requirements.

Roofscape question #2

Aaron,

the same condition exists at the transition from the entry concrete to the pathway by area 3. Carina had an idea but I can't quite remember the details. Considering the slope, this will be a constant maintenance issue with decomposed granite spilling onto the concrete.

adequate drainage in areas 9 and 13

Aaron,

in area 13, we would like to plant a small tree and grasses. Carina and Martin told us there was an adjustment that should be made to the proposed those "planter" walls to accommodate adequate drainage. I think the change was from a slab at the bottom to a spread footer. I think we should also make sure the same thing is happening in area 9.

thanks, Karla

Beam Clarification

1. Are these all the beams and are they located correctly on this plan?

YES, the beams are in the correct location, please note the added item "j" which are skylight beams.
2. Are the widths correct as shown on the plan?

YES.
3. Please go through the table and confirm whether beams are proud above the roof deck or turned down?

Please see updated table.
4. What are the heights of the beams, especially, A, B, and E as they will have an uphill (12") and down hill height?

The heights of the upturned beams are 12" above roof slab as they are parallel with the slab. Please note item "E" is a downturned beam.
5. What happens to the paths when a beam crosses, i.e. on the lower roof around areas 3 and 4?

The roof pedestrian ramp is at a 1:20 slope, which causes the distance between top of roof slab and top of walking surface (DG) to vary. This 1:20 slope accommodates the 12" height of the beam. We are looking at a detail for a steel plate to cover the beams where this intersection occurs (2 locations), while the DG would come to meet the plates.

Also can you please confirm whether area 8 is ground level or actually part of the green roof system?

Areas 8,9 & 13 (please note the added item "13") are NOT part of the green roof system.

Beam Clarification

beam clarification

Aaron,
Here is a plan of beam locations as S2.4 is outdated. The beams are labeled from "A-I" and there is a table on the lower right. Please clarify the following asap in order to specify stabilization anchors and pin down soil depths:
1. Are these all the beams and are they located correctly on this plan?
2. Are the widths correct as shown on the plan?
3. Please go through the table and confirm whether beams are proud above the roof deck or turned down?
4. What are the heights of the beams, especially, A, B, and E as they will have an uphill (12") and down hill height?
5. What happens to the paths when a beam crosses, i.e. on the lower roof around areas 3 and 4?

Also can you please confirm whether area 8 is ground level or actually part of the green roof system?

Please post your response on the blog so all of us have immediate access.

thanks, Karla

Answers to Roofscape Questions

Our comments are as follows:

1. Slope stabilization: With the wall layout, the only viable approach to support the steep slopes would appear to be by suspending cellular confinement webs or high-strength geogrid from the top of the slopes. Since the pitched areas are transected by walls, this will mean that attachments will be required along at least 5 different wall segments and also at the structural bean on the far west of the project. These attachments could take the form of stainless steel anchors that are either cast into the walls or installed by drilling into the finished walls. In our opinion, the spacing between anchors should not be more than 18”. Once the thickness of the soil layers in planted zones 3, 4, and 5 are established, Roofscapes, Inc. can compute the static pull-out forces for the anchors. The height of the anchors above the slab will depend on the final design for the landscape. Moment forces associated with these anchors will have to be taken into account for the design of the walls.

This sounds like a good approach. Please provide drawings and specification that we can send to our structural engineer for review.

2. Border edging: In transitions between decomposed granite and planted areas (associated with planted zones 1 and 10, some sort of structural edge will be needed to stabilize the decomposed granite walkways. While this could be custom fabricated stainless steel, we believe it would be considerably cheaper to cast curbs at these locations (green lines on the layout).

The planted zones you refer to are defined by planter walls, so those should not be an issue. However, your point does apply to defining zones 11,12, and 4 (in some areas) from the walkways. We were thinking if the material can be kept below grade so that it is a not visable, would a plastic fence be more cost affective.

3. Walkway transition: We would like to receive a definitive cross-section showing the transition between the decomposed walkway the planted zone 10. We believe that the most practical solution for this transition will be to install the decomposed granite (and curb) over a high-strength sheet drain. This will allow percolated rainfall and excess irrigation water to flow underneath the walkways. Effective uniform drainage of the planted zones is essential. Alternatively --- the walkways could be constructed as barriers to flow. In this case an efficient subsurface drainage network will be required to collect underflow and convey it to an area drain located within zone 10.

See detail attached. We have a drain board specified for the entire roof (1" ) and up the planter walls (3/8").

4. Barriers to flow: Many of the walls, unless modified, will provide barriers to water drainage. There are two possibilities: a) install these walls over high-strength sheet drains that will allow free flow of water under the length of these walls, or b) provide substantial scupper openings at all low points. We recommend building rectangular scuppers into the walls, each several inches high and a foot, or more, in length. We can work with the design team to determine how best to design and position scuppers.

Refer to detail attached (from #3). We had planned on providing weep holes at the bottoms of walls to allow drainage of water. Please provide a drawing showing the size and locations of weep holes so that we can submit these to our structural engineer. Please note that the engineer has already given us a max penetration through beams (of which we have a few we will need to drain through) of 2" diameter. You mentioned that circular penetrations are not as effective as rectangular. Please confirm your preference.

5. Flow patterns: Based on Drawing A2.1e and P-2, it appears like the rows of drains located on the north and south perimeters of the building as well as the row immediately south of the ramp will serve only the narrow planters in these areas. In particular it appears like the southern row cannot be effective in capturing runoff from the adjacent and up-gradient planted areas and walkways. Is there a plan to connect the areas north of the high parapet wall with these drains? We can be of assistance in suggesting some solutions.

I believe the row of perf pipe on the north is no longer necessary and is an artifact from an older design. The intention of the southern row, at the perimeter of the building, was to help carry water in that narrow planter towards the west. Please advise if you believe this to be true. I am not sure that the row south of the pedestrian ramp helps either; please advise.

6. Waterproofing flashings: We understand that most, or all, of the walls will be constructed using shot-crete. Will this concrete be hydrophobic? We are concerned that if this concrete can absorb water, it will become necessary to flash the walls at least 6 inches above the soil layer. This will have aesthetic and cost implications. There are many possible solutions for flashing the walls. We would be happy to discuss these with the team.

Our shotcrete walls are all 5000 psi concrete. Given that and the attached waterproofing detail, the flashing is a secondary measure. Will we have plantings that can cover the flashing if it is 6" above the soil? Can this be reduced at all? Please advise.

7. Irrigation: Unless 2” diameter sleeves are installed across and under the various walls, curbs, and walkways, stub-ups for irrigation will be needed in every planted zone. Also, the irrigation valves and controls can be either centralized inside the building (e.g., in a closet or utility space) or they can be placed on the roof. The downside of placing them on the roof will be that each irrigation zone will require its own valve chamber (typically 8”-12” high, 15” wide and 24” long. These will be visible.

2" diameter sleeves are being provided under the planter walls and walkways. Irrigation valves and controls will not be inside the building but in the planter areas. How many zones do you calculate we will need? My understanding is that these boxes will be flush with grade- lets work together to be strategic about where these are placed so that they are not in highly visible locations.

Preliminary Design Presentation

Conceptual Thoughts

Landscape is about memory, our memory and the land’s memory. We remember a flower’s scent, the taste of berries from our grandmother’s yard, and sound of grasses blown about by the wind. These memories stay with us, returning from the recesses of our minds, set off by sensory triggers.

There is also the memory of the earth, the soil, and the plants. Throughout the year and over the years, these elements remember to repeat the cycles of birth, life, death and birth again.

As Simon Schama writes in “Landscape and Memory,” from the pyre rises the phoenix, that through a mantle of ash can emerge a shoot of restored life.”

Plants remember to send shoots up, flower and die back. As designers, we call this cycle the earth’s memory, and it predates and transcends man’s role on the earth. This landscape is earth’s memory of hope, love and beauty. While these words were invented by our species, we believe these qualities reflect what was already there.

“The heart, to be sure, always has something to say about what is to come, to him who heeds it. But what does the heart know? Only a little of what has already happened.”

-I promesi sposi chapter viii (Georgio Bassini, “The Garden of the Finzi-Continis”)

The metaphors of hope, love and beauty endure in this landscape through a subtle mood created by quiet shades of green grasses and grass like plants. The unique, evocative features of ornamental grasses,enhanced by wind and light,fashion a landscape that seems to float and sway above the building, tethered by the distinctive lines of the parapet walls. The colors of the plants,blue gray and sea greencomplement the white, Colton concrete and translucent, light green glass of the building.

There are two views to this landscape, the macro and the micro. From far away one sees the plant vocabulary quietly transition from the manicured grass in the park to the looser, ornamental grasses on the roof. The similar textures naturally lead the eye from ground to sky. While the architecture creates a distinctive elegant form, the grasses tie the whole building back into the earth.

Upon entry, exit and strolling on the roof, the landscape experience is one of light, in contrast to the interior architectural spaces. Up close, the audience sees the details of fluffy, seed heads and the structure of grasses peaking out above the guard rails and the parapet walls. Spare accents of flowering bulbs generate punches of color in the central roof areas. These three central areas are naming opportunities for “Enlightened Gardens,” as well as the ground level east of the monument, where trees could be added to the existing California Sycamore trees.Light to dark to light. Leave with hope and purity.

We propose a simple mix of grasses ranging in height from one to four feet. On the lower levels and as a transition to the park lawn beyond, we would like to use Carex or Sedge, a grass like plant requiring low water and infrequent mowing. The average soil depth on the roof will be 12”, however to accommodate structural beams, the soil level will undulate and flow like the curvilinear shapes of the concrete walls.

Time-critical issues

Following a conference call with Karla Dakin and Lisa Benjamin, several time-critical engineering design issues came up. We would like to resolve these with Winters-Schram and Belzberg Architects before the concrete is cast.

To aid the discussion an annotated site plan is posted below based on A2.1a 10-22-09: ADA walls, 42” or higher (red), planted areas are numbered (orange), low curbs/parapets surrounding planted areas (blue), proposed curbs surrounding planted areas (green), and walls/beams where anchors must be installed are shown as broad blue lines. The highlighted areas show the decomposed granite walkways.

Our comments are as follows:

1. Slope stabilization: With the wall layout, the only viable approach to support the steep slopes would appear to be by suspending cellular confinement webs or high-strength geogrid from the top of the slopes. Since the pitched areas are transected by walls, this will mean that attachments will be required along at least 5 different wall segments and also at the structural bean on the far west of the project. These attachments could take the form of stainless steel anchors that are either cast into the walls or installed by drilling into the finished walls. In our opinion, the spacing between anchors should not be more than 18”. Once the thickness of the soil layers in planted zones 3, 4, and 5 are established, Roofscapes, Inc. can compute the static pull-out forces for the anchors. The height of the anchors above the slab will depend on the final design for the landscape. Moment forces associated with these anchors will have to be taken into account for the design of the walls.

2. Border edging: In transitions between decomposed granite and planted areas (associated with planted zones 1 and 10, some sort of structural edge will be needed to stabilize the decomposed granite walkways. While this could be custom fabricated stainless steel, we believe it would be considerably cheaper to cast curbs at these locations (green lines on the layout).

3. Walkway transition: We would like to receive a definitive cross-section showing the transition between the decomposed walkway the planted zone 10. We believe that the most practical solution for this transition will be to install the decomposed granite (and curb) over a high-strength sheet drain. This will allow percolated rainfall and excess irrigation water to flow underneath the walkways. Effective uniform drainage of the planted zones is essential. Alternatively --- the walkways could be constructed as barriers to flow. In this case an efficient subsurface drainage network will be required to collect underflow and convey it to an area drain located within zone 10.

4. Barriers to flow: Many of the walls, unless modified, will provide barriers to water drainage. There are two possibilities: a) install these walls over high-strength sheet drains that will allow free flow of water under the length of these walls, or b) provide substantial scupper openings at all low points. We recommend building rectangular scuppers into the walls, each several inches high and a foot, or more, in length. We can work with the design team to determine how best to design and position scuppers.

5. Flow patterns: Based on Drawing A2.1e and P-2, it appears like the rows of drains located on the north and south perimeters of the building as well as the row immediately south of the ramp will serve only the narrow planters in these areas. In particular it appears like the southern row cannot be effective in capturing runoff from the adjacent and up-gradient planted areas and walkways. Is there a plan to connect the areas north of the high parapet wall with these drains? We can be of assistance in suggesting some solutions.

6. Waterproofing flashings: We understand that most, or all, of the walls will be constructed using shot-crete. Will this concrete be hydrophobic? We are concerned that if this concrete can absorb water, it will become necessary to flash the walls at least 6 inches above the soil layer. This will have aesthetic and cost implications. There are many possible solutions for flashing the walls. We would be happy to discuss these with the team.

7. Irrigation: Unless 2” diameter sleeves are installed across and under the various walls, curbs, and walkways, stub-ups for irrigation will be needed in every planted zone. Also, the irrigation valves and controls can be either centralized inside the building (e.g., in a closet or utility space) or they can be placed on the roof. The downside of placing them on the roof will be that each irrigation zone will require its own valve chamber (typically 8”-12” high, 15” wide and 24” long. These will be visible.

site photos