Basement Waterproofing
keep in mind, mortar itself is not impervious to moisture. there are additives that can be added to mortar and 4000 psi concrete, say on a floor, comes close. these wall will never be ideal. even if you get it good, it will need maintenance every few years.
Brownstone Home Inspection
in General Discussion 13 hrs ago
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owest | 21 hrs ago
Any recommendations for masons/water-proofing contractors that repoint basement stone walls where mortar has failed?
Brownstone Home Inspection | 21 hrs ago
simple repointing and parging will not hold water back. The best way to do this is by “positive side” water proofing (on the outside). because this is an expensive undertaking, people often do “negative side” water proofing (on the inside using liquid applied products). know that negative side water proofing fails because the weight of the water pressing on it will cause the liquid product to decouple with the wall.
Before calling a contractor, read about negative side water proofing so you have an understanding of some of the products and challenges. when the contractor is on site, talk about some of the products. if he has not heard of some of them or cannot talk to them or offer up similar products that do what you are talking about, he is not who he says he is (as a professional, we get through these questions on the initial phone call so we do not waste time).
i do water leak investigations on the upper portions of buildings. i do not usually come out for basements because water is often everywhere outside these houses. even if you pour a pad with high psi concrete to help move water away, it will go in the ground and move laterally to your wall.
steve
www.brownstonehomeinspection.com
BobMarvin | 19 hrs ago
So Steve, are you saying that cellars like mine, with rubble foundations, will always be somewhat damp?
Brownstone Home Inspection | 13 hrs ago
robert:
i tell people that more often than not, there will be moisture (water) coming in through the mortar or high humidity in general. i am using a hygrometer and see readings of 50% – 72% and these are too high. readings of 60% in the air can push the moisture content of wood above 25% and we can see termites thrive. readings over 50% can support mold in dark places. that is what i see in MOST places in the city but sometimes we get an area that has historically remained dry (as evident by no inactive termite damage; most brownstones have some termite damage. if someone asks, i will elaborate on why and what this means for this type of construction).
some of the high humidity is brought on by seasonal wet periods and some are ever present conditions (a lot of water in the ground).
instead of spending money on a loosing battle for nothing, i say run two small humidifiers in these basements. if there is water pouring in through the mortar joints, go ahead and seal but that might not be perfect because if can come in through the floor.
I did have someone write me today about these drains installed around the perimeter that catch the water and direct them to a sump pump. if things are that bad, i can say that they do work because my aunt had one installed and it worked and i speak to customers who have them. i see them all the time. but water has to be directed to the drains and that can be problematic.