Vapour Barrier or Drylok??


Old 01-10-00, 09:26 PM
Visiting Guest
Posts: n/a

I was under the assumption that Drylok was
just a cement sealer and a vapour barrier made of plastic was still needed. The contractor finishing my basement said that the Drylok is all that's needed and will act as the vapour barrier. The Drylok was completed, only 1 coat was sprayed on, and there are still many pinhole and missed areas. They feel this is adequite coverage and it will be fine.....any comments would be appreciated...
Sponsored Links
Old 01-11-00, 03:26 AM
Visiting Guest
Posts: n/a

Drylok can act as a vapor barrier also, though it is not used that way very often. I
don't think it would be appropriate to comment on your basement job, without first seeing it. If your contractor is reputable,
he will warrent his work. This is kind of between you and him.

Jack the Contractor
Old 01-11-00, 04:26 AM
Visiting Guest
Posts: n/a

There are 3 sides to the basement vapor barrier question. Each side has its ardent supporters. Your contractor has chosen the 'none needed' position. Its just as valid as the other 2.
Old 09-06-05, 08:14 AM
Visiting Guest
Posts: n/a
The DryLock website indicates a minimum of 2 coatings, and specifies that pinholes should be covered.

I've also read in a basement remodeling book that a plastic vapor barrier on the outside of the studs will [help to] prevent moist air from inside the basement from reaching the basement walls where it could condensate.

So the layers go like this:
Basement wall (cement, stone, brick, whatever)
DryLock (2-3 coats)
Studs / framing, optionally filled with insulation
Plastic vapor barrier

Old 09-06-05, 10:07 AM
Join Date: Mar 2005
Location: USA
Posts: 6,130
Received 0 Votes on 0 Posts
Vapour Barrier or Drylok??

Almost every coating can be a vapor barrier. It just depends how thick it is and how many coats. A breathing paint can become a vapor barrier with a number of coats.

With coatings, there is a range of vapor-proofing (or lack of breating) - it is not a yes or no situation.

Films are different since they are produced in a factory and can be tested before application.

I doubt there is any guarantee that Drylok is a vapor barrier.

Old 02-01-07, 12:58 PM
Join Date: Feb 2007
Posts: 21
Received 0 Votes on 0 Posts
I would say it all depends.If you have had problems with moisture in the past,then you would want to use drylock.Be sure to use at least the min.amount of coatings suggested.To be on the safer side of things I would also want the vapor barrier done.It may cost more money,but in the long run it will be worth it.As for the contractor saying that the pin-holes are's a lie.That is a major reason why industrial coatings fail.A pinhole is a defect in the coating and acts as an area for moisture to permeate the substrate(aka.your concrete).It sounds like your contractor is just being lazy!What can happen is that if the drylock fails and there isnt a vapor sheet on the inside of your finished dry-wall then moisture could eventually lead to mold.It will be costly to fix this because you will have to tear down your drywall to fix the problem.Contact a sherwin-williams store for the exact directions on how to apply the dry-lock along with the recommended coatings to use.
Old 02-01-07, 02:00 PM
Join Date: Mar 2005
Location: USA
Posts: 6,130
Received 0 Votes on 0 Posts
Vapour Barrier or Drylok??

Older thread (2005) -

A paint salesman is probably not qualified to speak on waterproofing basements although he may know everything about paint as a decorative or protective coating for above grade walls.

He probably is not even aware of Thoroseal that has been a universally accepted mataerial for concrete waterproofing, repair and restoration for the last 50+ years. It is normally not promoted to the DIY market, but has been used on commercial, residential, industrial, institutional and civil (dams, etc.) projects.

Old 02-01-07, 02:22 PM
Ed Imeduc's Avatar
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 18,389
Received 0 Votes on 0 Posts

For what the cost is . Just hang a 6 mil poly over the wall from the sill plate. After they are done with the drylock.
Like said Id go for the Thoroseal . We use it a lot.
Old 02-01-07, 03:14 PM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 46,043
Received 118 Votes on 105 Posts
Wow, this thread originated 7 yrs ago.

For the record - for drylok or similiar coatings to be effective they must be brushed or rolled to work the material into and filling the pores. Spraying is acceptable as long as it is back rolled!
Old 02-19-08, 11:52 AM
Join Date: Feb 2008
Posts: 1
Received 0 Votes on 0 Posts
WOW 7 years old!

Well now it is 8!
Old 02-20-08, 01:19 PM
Taipans's Avatar
Join Date: Sep 2006
Location: Wentzville, MO
Posts: 72
Received 0 Votes on 0 Posts
Originally Posted by Ed Imeduc View Post
For what the cost is . Just hang a 6 mil poly over the wall from the sill plate. After they are done with the drylock.
Like said Id go for the Thoroseal . We use it a lot.
I posted a question about this very thread earlier today. (with pictures)

But since I am now not being so stupid and using the search feature I came across this one! Wanted to comment on the above even though its an old reply.

I was told by "Woods Basement" company to "put" plastic over the foundation wall and let it tuck into the sill at the bottom. Since my parameter water guard system is causing some condensation to appear a few inches past its opening.

Anyhow, since someone else suggested this I was worried it might cause more of a chance for mildew and mold to grow since you "trap" the water in without good air circulation.

But in any even if you do hang it from the sill plate, how do you do so? With some kind of adhesive? Staples? And does it then hand losely down the wall?

Last, if you do this do you still need to put a vapor barrier between the studs and drywall?

Thank you very much I am completely stuck on this part!
Old 02-21-08, 07:36 AM
Join Date: Jan 2006
Location: usa
Posts: 209
Received 0 Votes on 0 Posts
drylock must be applied with 2 coats, the 1st being brushed on and the 2nd can be rolled on..make sure that there is no sight of the cinderblock. this job is not fun.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes
Ask a Question
Question Title:
Your question will be posted in: