| Author |
Message |
Lynn Javoroski
Senior Member
Username: Lynn_javoroski
Post Number: 26
Registered: 07-2002
| | Posted on Wednesday, June 18, 2003 - 10:58 am: |    |
The situation: a heliport on the 8th floor of a hospital with occupied space below. We will have 10 inches of concrete, a waterproofing system, and 4 inches of concrete as a topping. I'm proposing the use of Ashford Formula to seal the top concrete.
My question: What the heck is the best solution for the waterproofing system between? We've discussed bentonite, drainage pan, hot mopped asphalt, PVC membrane, etc., without being able to reach a decision. We need to be certain that no liquid will penetrate this system and that includes jet fuel A.
Ideas? |
(Unregistered Guest)
Unregistered guest
| | Posted on Thursday, June 19, 2003 - 12:07 pm: | |
Hot rubberized asphalt will be eaten by jet fuel. However what is the likelyhood of a spill? PVC may be stable but I'm not sure. Will the chopper be refuled at the hospital? I doubt that would be the case. If there was a fuel leak significant enough to penetrate through a 4" slab then I think you greater safety issues than waterproofing. |
Dave Metzger
Senior Member
Username: Davemetzger
Post Number: 45
Registered: 07-2001
| | Posted on Thursday, June 19, 2003 - 01:03 pm: | |
On airport work we have done, we have used CPE (Hypalon) for roofing because it is resistant to jet fuel. I have not used this product for waterproofing and don't know if it is suitable for this purpose. |
Robert E. Woodburn, CCS, CSI
Junior Member
Username: Bob_woodburn
Post Number: 3
Registered: 05-2003
| | Posted on Thursday, June 19, 2003 - 01:46 pm: | |
You might consider a coal tar pitch based system; if I recall correctly, its non-petroleum-based chemistry makes it resistant to deterioration from petroleum products. (It's used on roofs in petroleum refineries, which produce asphalt.) I heard years ago that the coal-tar pitch roof of the Houston's art deco landmark Gulf (Oil Co.) Building, a membrane sandwiched in between a concrete roof slab and topping slab, had lasted over 50 years without any problems. (Of course, coal tar BUR components today aren't quite the same as they were back then.) |
Robert E. Woodburn, CCS, CSI
Member
Username: Bob_woodburn
Post Number: 4
Registered: 05-2003
| | Posted on Thursday, June 19, 2003 - 01:55 pm: | |
(If this is an occupied existing hospital, instead of new construction, disregard my previous message; coal tar would be inappropriate due to fumes, even from the low-fuming variety.) (Not bentonite, either; even below grade it can be problematic...) |
Curt Norton, CSI, CCS
Intermediate Member
Username: Curtn
Post Number: 17
Registered: 06-2002
| | Posted on Thursday, June 19, 2003 - 02:52 pm: | |
This should be a new thread, I suppose, but what are the problems with bentonite below grade? |
Ron Beard CCS
Member
Username: Rm_beard_ccs
Post Number: 21
Registered: 10-2002
| | Posted on Friday, June 27, 2003 - 02:38 pm: | |
The problem with putting any just any material over top of a roofing membrane is that one runs the risk of voiding the roof warranty. It would be wise to stay with a material acceptable to the roof system manufacturer.
I suggest roofing the concrete structural deck with fluid-applied modified bitumen system and installing 6" of 100-psi StryoFoam [an acceptable roofing material]. A concrete topping can be placed over the StryoFoam. The 100-psi StyroFoam is manufacturered for the highway industry (usually not shown in the StryoFoam's Architectural catalog) but it is available. I've used this system successfully over fluid-applied membranes under excessively heavy rooftop planters and over an ambulance driveway over a vaulted boiler room in a hospital.
I've used the Ashford Formula sealer over concrete garage slabs and it appears to work well with petroleum products. I assume a special roof drain would be required to drain the heliport pad with special filters to clean the water before reaching the storm system. |
j smith
New member
Username: Specbuster
Post Number: 1
Registered: 07-2003
| | Posted on Wednesday, July 30, 2003 - 08:37 am: | |
There is an intregal concrete waterproofing additive the should work fine for your application..The product is C-1000 by the XYPEX corp. advantages are..
>Resists extreme hydrostatic pressure from either positive or negative surface of the concrete
>Becomes an integral part of the substrate
>Highly resistant to aggressive chemicals
>Can seal hairline cracks up to 0.4 mm
>Allows concrete to breathe>Non-toxic
>Less costly to apply than most other methods
>Permanent
Ashform Formula has no waterproofing capability and is a clear sealer ONLY..It will not bridge any future cracking.
|
j smith
Junior Member
Username: Specbuster
Post Number: 3
Registered: 07-2003
| | Posted on Wednesday, July 30, 2003 - 08:53 am: | |
The link for the Xypex product is
http://www.xypex.com/products/admix1_desc.html |
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