Q. I have a basement with standard masonry walls. There's a little "bump out" workshop that was put in sometime after the original house was completed. The owner cut through the original foundation to create a door and built an underground workshop there. An enclosed sun porch rests atop the workshop. The workshop is the dampest part of the basement. We keep finding puddles in one corner, sometimes up to a half-inch deep. This happens every few weeks, regardless of the weather. We have to take out the shop vac and vacuum it up.
That dries things out for a little while, but, inevitably, the water returns, and a portable dehumidifier doesn't seem to help. There are no visible cracks or condensation on the walls, and the water appears to either be bubbling up through the floor or through microscopic cracks at the base of the wall. (The floor is covered in 50-year-old asphalt tile and mastic, so we can't see whether there are any obvious cracks on the slab below.)
The rest of the basement is bone dry, including the other side of the workshop. We spoke with a few different basement waterproofing companies, all of whom told us that the only solution was to put in a sump pump. But that seems like overkill if the problem is only in one corner of this little part of the basement. What would you recommend? Short of digging out the foundation and resealing it from the outside, or repouring the floor, we're flummoxed!
A. If the puddles appear during any season and you don't see any wetness on the walls indicating condensation, it is likely that the water is coming through the walls. If it were coming through cracks in the floor, you would likely see white efflorescence in the joints between the old asphalt tiles. Check the grade around the entire foundation, as water can travel considerable distances before it finds a weak point. Make sure that the grade flows away from the foundation and correct any low or flat areas.
It is also possible that, when the "bump out" was built, a dirt ball fell on the footings before the walls were erected and, over time, water pooling at the base of the foundation has found its way inside at that point; I have seen this before, where the top of the footing was not thoroughly cleaned before the wall forms were set up or the concrete blocks were laid. If the walls are made of poured concrete, you may want to try to waterproof them with one of the coatings available in hardware and building supply stores. However, if the walls are concrete or cinder blocks, do not waterproof them from inside, as their cores may fill with water and cause worse problems. If the condition is so small, as you say, you may just have to live with it.
I'll say this again in responce to this statement:
"If the walls are made of poured concrete, you may want to try to waterproof them with one of the coatings available in hardware and building supply stores"
Coatings don't work for long periods of time. They should only be used as a temperary solution if used at all.
The man, Henri de Marne is a little rough with the person asking for help. No one has to "live with" a wet basement. In fact no one SHOULD live with it because over long term not only is it damaging to your house but damaging to your health.
This is clearly a problem that's caused by both the land grade and something that's wrong with the footing/wall cold joint. I'm guessing there's not exterior drain system to speak of and it sounds like the area actually needs a bit of work.
Dinggy looking wood furtinure can be fixed with coatings and paints, not foundation walls.