I have a very leaky basement. The house was built in 1937

and the foundation consists of 2 courses of brick that were never

coated with anything. What is the best way to waterproof it?

My plan is to dig it up, clean it and coat it with a coating of

mixture of Type M Portland, lime and sand. Considering screening it

Before the cement ( or do you think that's overkill). After coating it

with hot tar. I will put a perforated drain in before backfilling it.


Comments or other options appreciated.

(Jeff) wrote in
:

On Thu, 03 Jul 2003 14:18:14 -0000, who wrote:


Hot tar would be a big mistake. First it is not waterproof. It is
technically considred dampproofing. Second it does not retain any
flexibility once cured. Third tar degrades over time in sub-grade
applications.

Go to a local contractor supply company, not Lowes or Home Depot, and
ask for Bituthene or a similar product. Comes in rolls and is
designed for exterior foundation waterproofing. Make sure you also
use a protection course over the membrane to protect it from puncture
during backfill. Apshalt board or blue board works fine.

Also consider backfilling to about 2' of finished grade with gravel.
It is important to not only stop the water from entering, but also to
drain it away to reduce stress on the foundation.

I considered the Bituthene approach, but after much research I
determined that for my particular application it was overkill. The
procedure to apply the membrame included priming the wall, applying
the product, covering the remaining seams with mastic. It seemed like
a real headache and pain in the ass to apply. Plus, I was told that
the primer they recommend doesn't last any longer than regular tar or
asphalt. Since he would be applying the membrane to brick, he's even
in worse shape t because the wall is not as smooth as a poured
concrete wall I was working with. I would have reservations about gaps
and air pockets which might occur over an irregular surface such as
brick. It seems to me that a couple of coats of a polymer modified
foundation coating would better cover all the imperfections in the
brick.

If you do decide to go with the Bituthene get the Bituthene 3000 or
4000 system NOT the Water and Ice product they make for roofing
applications.


The original poster mentioned that they were going to parge the wall first,
which would provide a smooth surface for application. Parging the wall is
sufficient for bituthene or similar products (given it is allowed to
properly cure prior to membrane application). It is NOT recommneded that
you use a polymer modified foundation coating as a base for the application
of pre-manufactured membranes. The polymer additive may cause outgassing
which would affect the adhesion of the membrane and possibly cause
degradation of the membrane.

The product is not that difficult to apply. The bigger headache would be
having to re-excavate to put on a true waterproof barrier.

The purpose of the primer is NOT the same as the tar. It provides no
waterproof characteristics and is only intended to facilitate initial
bonding of the membrane. The horizontal weight of the back fill renders
the long term adhesive properties of the primer moot.

The point was that you have to put on a true waterproof barrier that does
not degrade over time and remians elastic enough to span any cracks that
exist or may develop over time.

Trent© wrote in
:

On Fri, 04 Jul 2003 02:04:27 -0000, who wrote:


The point was that you have to put on a true waterproof barrier that
does not degrade over time and remians elastic enough to span any
cracks that exist or may develop over time.

ThoroSeal.


Have a nice week...

Trent

Help keep down the world population...have your partner spayed or
neutered.


Once again Thoroseal is not appropriate as it does not retain any
elastomeric properties. It is also not appropriate under constant
hydrostatic head as the primary waterproof barrier. I have never seen it
spec'd for subgrade exterior waterproofing by professionals.

Even the makers of Thoroseal do not claim that is elastomeric.

If you're going to do it, do it right.

Trent© wrote in
news
On Fri, 04 Jul 2003 15:17:49 -0000, who wrote:

Trent© wrote in
m:

On Fri, 04 Jul 2003 02:04:27 -0000, who wrote:


The point was that you have to put on a true waterproof barrier that
does not degrade over time and remians elastic enough to span any
cracks that exist or may develop over time.

ThoroSeal.


Have a nice week...

Trent

Help keep down the world population...have your partner spayed or
neutered.


Once again Thoroseal is not appropriate as it does not retain any
elastomeric properties. It is also not appropriate under constant
hydrostatic head as the primary waterproof barrier. I have never seen
it spec'd for subgrade exterior waterproofing by professionals.

That may be. But there's sure a lot of rework being done out
there...original work done by the 'professionals'.


Even the makers of Thoroseal do not claim that is elastomeric.

If you're going to do it, do it right.

Never had any problems with it.


Have a nice 4th weekend...

Trent

Help keep down the world population...have your partner spayed or
neutered.


Not having had a problem with it does not mean it is acceptable use of the
product. Yours is one instance. I have, however, had to re-do work where
Thoro-seal has been used on exterior below grade. Thoro-seal is a very
good product when used on the correct application.
Coating an exterior, sub-grade foundation is not a proper use and the
advice to use in lieu of a product designed specifically for the purpose is
irresponsible. I would suggest that the original poster check with an
architect or building engineer rather than be confused by the
misinformation offered on this group. Also check with the AIA for
acceptable foundation waterproofing methods. You will not find Thoro-seal
as one of them.