Contractor Talk - Professional Construction and Remodeling Forum banner
1 - 14 of 14 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter · #1 ·
I have been roofing a long time and I will never understand why rubber companies want you to use lap seal. Every EPDM rubber roof I have ever been on the lap seal is always cracked up in 3 years or less. You can not trust glue and primer by itself so I use solar seal it is the best chaulk there is. I think it is even better than NP 1 . I had allot of problems with geo cell, Its not sticky enough . It will hang off a brick chimmney like spaghetti. With solar seal there will never be any leaks , it is a commercial roofing chaulk but allot of people will use it for siding. There is allot of diffrerent types of chaulk that almost have the same name. Solar seal is hard to find so I would order strait from the supplier
 

·
Commercial Roofing
Joined
·
1,220 Posts
Isn't the lap seal a temporary measure designed to seal the lap until the seam adhesive can fully cure?

It is not needed with seam tapes, correct?
 

·
Commercial Roofing
Joined
·
99 Posts
EPDM lap seal

Most EPDM installations now use Inseam Tape (double-sided adhesive) for seams and endlaps. Scrub the overlapped and overlapping areas with ScotchBrite pads dipped in QuickPrimerPlus or some equivalent product, put down the tape (sticky side down), flop the overlapping portion of the sheet over it, then pull off the paper backing to expose the upper adhesive surface. Roll thoroughly and you are done--no lap seal, except around patches, flashings, etc.

Lap seal used to be used as insurance for laps made with splice adhesive. Inseam tape is a LOT better.
 

·
Registered
Joined
·
2,565 Posts
Lap seal used to be used as insurance for laps made with splice adhesive. Inseam tape is a LOT better


My understanding was the lap sealant was to keep dirt from getting under seam(capillary action) and causing an uplift at edges leading to failure.
It was suppose to be put on after 24hrs,so all gases from seam seal had a chance to escape.
 

·
Registered
Joined
·
291 Posts
Lap seal should still be used in some cases were seam tape is also used.

If your membrane is re-inforced, all raw or cut edges should be cualked with lap seal to prevent water from wicking into the scrim and destoying the membrane.
 

·
Shingler extraordinaire
Sales Estimator/ Project Manager
Joined
·
9,890 Posts
Solar seal is the best caulk on planet Earth. I use it on all my roofs, slope or flat.
 
Joined
·
110 Posts
I have been roofing a long time and I will never understand why rubber companies want you to use lap seal. Every EPDM rubber roof I have ever been on the lap seal is always cracked up in 3 years or less. You can not trust glue and primer by itself so I use solar seal it is the best chaulk there is. I think it is even better than NP 1 . I had allot of problems with geo cell, Its not sticky enough . It will hang off a brick chimmney like spaghetti. With solar seal there will never be any leaks , it is a commercial roofing chaulk but allot of people will use it for siding. There is allot of diffrerent types of chaulk that almost have the same name. Solar seal is hard to find so I would order strait from the supplier

ALLIED carries this stuff...prob also the rest of the big guys.
 

·
Registered
Joined
·
17,271 Posts
cant get that stuff here in N.J. unless its in a 16 oz tube
you have to buy a special gun for it,has something to do with the e.p.a. and voc's
 

·
Registered
Joined
·
8,573 Posts
I still use lap/edge sealant even with seam tapes. In addition, I saw a product last year in a mag but can't remember the name. It was a combination primer, adhesive and lap sealant all in one. I wanted to give it a try on a repair once to see how it worked. S best I could tell it was probably a neoprene caulk.
 

·
Registered
Joined
·
1 Posts
try geocel 4500 for epdm

Geocel 4500 is some nice stuff. It acts as caulk, adhesive and it can completely cure under water. You wont have any cracking or peeling problems with this stuff. great for repairs or new installs
 

·
Registered
Joined
·
57 Posts
Try to eleminate Lap Sealant

I install a lot of Firesone EPDM, and you should avoid dependending on Lap Sealant - it degrades in the sun.

Firestone switched to a whole line of products called "Quick-seam" these are all details which are 2-sided tapes. Most of these items eliminate the need for lap-sealant.

-- Firestone Building Products/Technical Data Base




John in MN
 
1 - 14 of 14 Posts
Top