Parking Structure Traffic Topping/Waterproofing
Parking Structure Traffic Topping/Waterproofing
(OP)
We normally provide a hot-applied waterproofing membrane overlaid by 2" to 3" of asphalt wearing course, as the waterproofing system on parking garage roof parking levels (CSA Standard S413 requires that cast-in-place parking structures be protected against corrosive deicing chemicals and leakage by a waterproofing membrane). An alterrnative to the hot-applied membrane has been proposed, of using a factory-made torch-applied membrane (overlaid by asphalt). There are advantages and disadvantages of a torch-applied membrane. Althpough we have designed many parking structures with a hot-applied membrane overlaid by asphalt wear course, we have not designed any with a torch-applied membrane and asphalt wearing course (we have though seen torch-applied mmebrane overlaid by concrete topping for loading dock ramps in a building).
QUESTIONS:
Has anyone had experience with torch-applied membrane overlaid with asphalt on roof level of parking?
How did it work out and how has it performed over the years?
Any problems with the asphalt attributable to the torch appled membrane?
QUESTIONS:
Has anyone had experience with torch-applied membrane overlaid with asphalt on roof level of parking?
How did it work out and how has it performed over the years?
Any problems with the asphalt attributable to the torch appled membrane?






RE: Parking Structure Traffic Topping/Waterproofing
This most significant issue I've seen with any torch applied membrane is surface preparation and workmanship. Also, many torch applied applicators (and manufacturers) will use "seam only" torching.....bad idea. Watch for it and don't let them.
For SBS modifieds, the melting point is lower; however, these usually have thinner reinforcing mats so there is less "asphalt" to melt.
For APP modifieds, the melting point is much higher and there must be care in keeping the material flowing under the torch.
Also, concrete will need to be consistently primed and be careful of "heat sinking"....large mass of concrete, cools quickly.
RE: Parking Structure Traffic Topping/Waterproofing
RE: Parking Structure Traffic Topping/Waterproofing
This is their CCW-500 product - found here.
It has a waterproofing product with a drainboard/protection board system topped with non-structural pavement.
RE: Parking Structure Traffic Topping/Waterproofing
RE: Parking Structure Traffic Topping/Waterproofing
You could contact Carlisle (or any other similar company that provides similar products) and ask them about the asphalt paving vs. concrete.
RE: Parking Structure Traffic Topping/Waterproofing
I will follow up on your suggestion to contact a torched-on membrane supplier and go see at least one of their projects to see how it is doing. I had already asked the contracor to give us the name of at least one such project, but so far he has not got back.
Given that no one has yet responded with an answer that they do use torch applied membrane overlaid with asphalt wearing course on parking garage floors, I am thinking that that is not commonly done...but maybe someone will still respond that they do.
RE: Parking Structure Traffic Topping/Waterproofing
TP-180-FF-Base 3 mm thick, by IKO (we had specified 6 mm thick (i.e. 2 layer reinforced) hot applied rubberized asphalt membrane.
RE: Parking Structure Traffic Topping/Waterproofing