Technical question - Good adhesive for densdeck to BUR

We are doing 100 square mod. bit. torch down. and need to apply densdeck to an existing BUR surface and need a good , inexspensive , adhesive. Any ideas??

It is a concrete deck so we cannot mechanically fasten it like the metal roof deck below it.

We need a 5 gallon bucket type glue or tar to just mop down and adhere the densdeck, let cure, then torch mod. bit down.

We have done 100’s of torch downs but never had to adhere the dens deck this way. just have always had to do it to a metal deck.weird.Thanks


Your not allowed to install screws and plates?

Roto hammer drill and 6 inch 7/32 drill bits will do the trick! Drill the holes into the concrete then install 1/4 inch x 4 in screws (depends on how deep you want to go).

But you will have to fight the rebar though…will toast your bit in a jiffy.

Insta-stik requires a clean, dust-free substrate. It will NOT adhere to asphault, ever. In order to use adhesive you must tear off the existing roof, clean the dust and then use the adhesive.

If you plan to leave the existing roof, RG is correct, you must drill and pin the densdeck. If it is actual concrete, use CD pins, if it is gypsum or lightweight concrete, either use Oly Lok nails or Hammer drill and light deck fasteners, or gyptec screws. If you use these you need to apply a base of softer insulation such as polyisocyanurate (iso), fasten that to the deck with the fasteners I’ve listed, then apply durarock or densdeck using foam adhesive. You cannot pin the densdeck to a gyp deck because the densdeck will constantly pull against the pins with enough force to pull them out. Usually that takes only a few minutes.

Olympic OlyBond would work well. Use it to stick down the Dens Deck Prime and install your mod bit over that. Make darn sure the existing bur is dry. If not, the Dens will deteriorate and the whole system will be toast.

Donl’s right, Olybond will adhere to BUR and Mod-Bit providing it is dry and free from dust and debris.

I don’t know, but I can tell you not to use dual cartridge adhesive. I have seen a lot of those fail around here.
I think adhering to a BUR at all is probably a bad idea. If customer can’t afford anything else I guess you have to figure something out. Careful what you warrantee.

The only time I see it fail is if the applicator installs the insulation before the two component adhesive achieves its “string” time. Many applicators try to put the foam down and immediately install the insulation…this destroys the cells and makes the adhesive go back to a liquid. Take note, the industry is moving away from fasteners and heading toward adhesives. You see that not only in commercial roofing but in tile roofing.

Olybond will work well. This time of year you have beware of falling temps. I recall using it and then the next morning the insulation we set between 3 o’clock and 4:30 had to come off and replaced. The temps were OK when we set it, but dropped too quickly for the product to properly set.

Great point! Temp does cause problems. When in cold weather get the winter formula. Moisture will also affect the set.