Water in Basement
#1
05-13-09, 12:10 PM
Water in Basement
Hello All -
For several years in a row now, we've gotten water in our basement in the springtime. Only happens once, maybe twice per year when we get real intense and prolonged rain events. What happens is water will come up from the intersection of the floor slab and footing wall.
I've done a good deal of research and think the the best way to take care of this issue once and for all is to remove the floor slab to about 18" inside the footing wall, install drain tile and porous granular fill underslab, route to a sump pit, then repour the floor slab over a corrogated or dimpled sheathing product.
My question, to anyone that is familiar with this type of work, is what to do if you have some framed stud walls on inside face of some of the perimeter foundation walls (stud walls are purley for drywall finish purpose and serve no structural purpose)? Are they going to have to be demo'd to do this work? Or can you remove the slab without having to remove the stud wall? In my case - I have framed stud wall on probably 1/2 the total perimeter, the rest is completely unfinished.
I also know of 1 location (possibly two) where some plumbing drain lines are running on top of the footing (perpendicular to footing - so a very short segment of the footing has drain line on top of it). In these cases, do you just have to dig and install the drain tile under the drain line (is essence, it would look something like a p-trap when you dig the drain tile under the drain line)?
Thanks!
For several years in a row now, we've gotten water in our basement in the springtime. Only happens once, maybe twice per year when we get real intense and prolonged rain events. What happens is water will come up from the intersection of the floor slab and footing wall.
I've done a good deal of research and think the the best way to take care of this issue once and for all is to remove the floor slab to about 18" inside the footing wall, install drain tile and porous granular fill underslab, route to a sump pit, then repour the floor slab over a corrogated or dimpled sheathing product.
My question, to anyone that is familiar with this type of work, is what to do if you have some framed stud walls on inside face of some of the perimeter foundation walls (stud walls are purley for drywall finish purpose and serve no structural purpose)? Are they going to have to be demo'd to do this work? Or can you remove the slab without having to remove the stud wall? In my case - I have framed stud wall on probably 1/2 the total perimeter, the rest is completely unfinished.
I also know of 1 location (possibly two) where some plumbing drain lines are running on top of the footing (perpendicular to footing - so a very short segment of the footing has drain line on top of it). In these cases, do you just have to dig and install the drain tile under the drain line (is essence, it would look something like a p-trap when you dig the drain tile under the drain line)?
Thanks!
Last edited by rkelachim; 05-13-09 at 01:54 PM.
#2
05-13-09, 05:52 PM
I wouldn't do it that way. I would dig outside to about 4 inches below the footing. There is a membrane that comes on a roll. It gets pasted to the foundation in such a way that it extends over the footing & below it. Then you throw some gravel on it & backfill.
#3
05-13-09, 07:57 PM
Member
Water in Basement
Just a membrane will not do it well since you have a seasonal groundwater problem. and have to get rid of the water or it will just continue to go under the footing.
It shows up on the side because the joint between the slab and wall is never sealed and the slab can slide on the footing. You probably have water around the base all year long, but it just accumulates enough in the spring to move around more and find a way in.
It is not a good practice to cut out a continuous strip of floor parallel to the wall, since the floor slab provides lateral resistance to the wall and the slab resting on the footing is required to abut the wall. The best way to do it is remove sections 6' to 8' long separated the 12" sections to help provide lateral resistance to the wall base. Make sure the openings are long enough to thread in the perforated pvc pipe sections. Perforated corrugated is acceptable, but not as good, since it does flush itself clean. If you leave sections, they can be located where there are intersecting frame wall on the inside and they do not have to be disturbed.
Of course the easiest and cheapest thing is to install long (10') downspout extensions to get the water beyond the area that was excavated during construction. An underground line with a pop-up discharge is also possible, but in either case, you will need a positive slope to carry water away. - This does reduce the water around your basement wall, but does not do much for the groundwater, that usually can travel laterally at certain times.
Dick
It shows up on the side because the joint between the slab and wall is never sealed and the slab can slide on the footing. You probably have water around the base all year long, but it just accumulates enough in the spring to move around more and find a way in.
It is not a good practice to cut out a continuous strip of floor parallel to the wall, since the floor slab provides lateral resistance to the wall and the slab resting on the footing is required to abut the wall. The best way to do it is remove sections 6' to 8' long separated the 12" sections to help provide lateral resistance to the wall base. Make sure the openings are long enough to thread in the perforated pvc pipe sections. Perforated corrugated is acceptable, but not as good, since it does flush itself clean. If you leave sections, they can be located where there are intersecting frame wall on the inside and they do not have to be disturbed.
Of course the easiest and cheapest thing is to install long (10') downspout extensions to get the water beyond the area that was excavated during construction. An underground line with a pop-up discharge is also possible, but in either case, you will need a positive slope to carry water away. - This does reduce the water around your basement wall, but does not do much for the groundwater, that usually can travel laterally at certain times.
Dick
#4
05-13-09, 09:22 PM
Thanks concretemasonry!
You addressed one of my other big concerns too - the lateral resistance on the wall. Leaving that 12" segment is a good idea!
I did try the gutter exgtensions. I went so far as to run them 30 feet or so from the house. But it did not take care of the problem.
I did consider installing the draintile from the outisde, but decided to do the installation from the inside. Deciding factor was that we will be selling our home this summer and I didn't want to jeopordize our curb appeal by losing our nice, mature bushes around the house.
Another interesting part of the story here - I did try to call a local waterproofing contractor to get an estimate for this work. They couldn't even get out to do an estimate unitl mid-June and would not be able to do the work for a couple of weeks after that. Like I said, we're selling this house this summer and I just can't wait that long to get this work done. So I got to do it myself.
You addressed one of my other big concerns too - the lateral resistance on the wall. Leaving that 12" segment is a good idea!
I did try the gutter exgtensions. I went so far as to run them 30 feet or so from the house. But it did not take care of the problem.
I did consider installing the draintile from the outisde, but decided to do the installation from the inside. Deciding factor was that we will be selling our home this summer and I didn't want to jeopordize our curb appeal by losing our nice, mature bushes around the house.
Another interesting part of the story here - I did try to call a local waterproofing contractor to get an estimate for this work. They couldn't even get out to do an estimate unitl mid-June and would not be able to do the work for a couple of weeks after that. Like I said, we're selling this house this summer and I just can't wait that long to get this work done. So I got to do it myself.
