Chica­go Base­ment Water­proof­ing – Exte­ri­or Water­proof­ing Membrane

Oct 21, 2012 • By Matthew Stock.

Many Chica­go home­own­ers, when faced with water seep­age through their base­ment walls, think that smear­ing some­thing on the inside of the wall is the best way to stop it. There is no short­age of prod­ucts on the mar­ket for this pur­pose – ​“water­proof­ing” paint, hydraulic cement, even rub­bery gunk in spray cans – and a lot of so-called DIY experts who encour­age their use.

All this stuff is a waste of time and mon­ey. The most effec­tive way to stop water pen­e­tra­tion through a foun­da­tion wall is to apply a real water­proof­ing seal to the out­side of the wall – and I’m not talk­ing about ​“damp-proof­ing,” either.

Why an Exte­ri­or Water­proof­ing Mem­brane is the Most Effec­tive Way to Stop Foun­da­tion Wall Seepage

It may help to explain the dif­fer­ence between damp-proof­ing and water­proof­ing a foundation.

Both are what are called ​“pos­i­tive side” process­es that place a bar­ri­er between the out­side water and the exte­ri­or sur­face of the foun­da­tion wall. The DIY prod­ucts men­tioned ear­li­er attempt to cre­ate a ​“neg­a­tive side” bar­ri­er, one in which the water is allowed to pen­e­trate the foun­da­tion wall to be stopped on the inside before it reached the basement.

Damp-proof­ing, as the name implies, is a process designed to help pre­vent water pen­e­tra­tion only from moist soil and not ground water that is under pres­sure. It uses a thin, asphalt-based com­pound that is sprayed onto the foun­da­tion walls quick­ly, usu­al­ly dur­ing the con­struc­tion process. It doesn’t effec­tive­ly seal open­ings in the wall and is eas­i­ly dam­aged dur­ing backfill.

Exte­ri­or water­proof­ing, on the oth­er hand, involves the appli­ca­tion, either with a trow­el or heavy-duty sprayer, of a thick com­pound called an exte­ri­or water­proof­ing mem­brane, usu­al­ly asphalt-mod­i­fied ure­thane, that com­plete­ly seals the foun­da­tion walls and pro­tects them from ground water under pres­sure. It is effec­tive on any type of foun­da­tion, par­tic­u­lar­ly so on mason­ry like con­crete block, stone or brick.

Once a thick coat of the water­proof­ing mem­brane has been applied to the foun­da­tion walls and allowed to cure, it is often cov­ered with heavy-duty plas­tic drainage board. Fas­ten­ers for the board are installed before the mem­brane is applied so that they are sealed into the wall and don’t become sources for water pen­e­tra­tion. The drainage board not only pro­tects the mem­brane from wear or dam­age but it chan­nels ground water down, between it and the foun­da­tion wall, to any exte­ri­or drain tile sys­tem that lies next to the foun­da­tion footings.

The exte­ri­or water­proof­ing mem­brane, drainage board and exte­ri­or drain tile form an effec­tive sys­tem that will pro­tect the base­ment against even the worst wet soil and ground water con­di­tions. It is one of the most pow­er­ful weapons in the Chica­go base­ment water­proof­ing arsenal.

If your home was ​“damp-proofed” when it was built, that’s not a bad thing – cer­tain­ly bet­ter than noth­ing. But, if you are expe­ri­enc­ing seep­age through your base­ment walls then only an exte­ri­or water­proof­ing mem­brane will solve the prob­lem. At U.S. Water­proof­ing, we’ve applied water­proof­ing mem­brane to lit­er­al­ly thou­sands of homes and have the exper­tise to know exact­ly where it’s need­ed to solve the prob­lem at your home. Why not ask for our free advice?

Tags: exterior waterproofing, chicago basement waterproofing, basement waterproofing chicago, exterior waterproofing membrane

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