I Recently purchased a vacation home under an as is condition. The home has a a permenent wood foundation / basement. The wood I-beam floor joist run from the front wall to the back wall. The basement is a walkout, with the entire rear wall exposed, side walls partially exposed, and front wall backfilled to 1′ from top of the wall. The previous owner, so called builder, failed to install blocking at the top of the side wall to tie it into the joist/floor system. He also backfilled the basement after the floor was installed but before the first floor was built. This has resulted in failure of the basement walls. The top of side walls are bowed in about 1 1/2″ worst case. And the top of the front and rear walls are leaning toward the rear about 1″ worst case. The bottom of the walls are locked in place between the basement floor and the backfill. I am considering excavating the “clay/sand” back fill from around the foundation and straightening the walls.
Would like advice. Is this the right thing to do? If yes, any advice on how to do it? Or, should the house be lifted and the foundation walls be replaced? I would prefer to save the money and straighten the walls if this is a vialbe solution.
Replies
I am not an engineer, but I have an idea that may solve your problem. Dig outside the walls for a footing and concrete column. Depending on the spans between corners you would pour one or more columns. Bore holes thru foundation walls for acme threaded rod. Install plate washers and nut inside column, plate washer should be deeply imbedded. Wait a week after concrete is poured then install heavy duty channel iron vertically on foundation wall. Add washer and acme nut, then pull up with large pipe wrench to your satisfaction. There must be space between foundation wall and column or you won't be able to straighten your walls up. Acme rod about 1" dia. will work. This stuff is expensive but I reccomend it over bolt rod. The coarse threads on the acme rod won't strip as the bolt rod will probably strip under great pressure.Consult an architect or engineer for the feasability of this method, he'll tell you what size footing and column to build.
Mike
Thanks for feedback, your suggestions are very similar to what I had been think of doing. But, was not familiar with acme threaded rod. I'll check it out.
Mike
I suspect that he ment "allthread".
Acme thread is a special thread. I it is commonly used on vises and screw jacks.
Not very common.
Bill,
I did find some info under "acme Rod" at http://www.decristo.com. It is 1/2" to 1 1/2" Rod with acme thread.
Bill, Acme rod is used extensively by carpenters doing concrete formwork. Generally used in patent forms and other heavy duty applications. Supply houses that cater to commercial builders carry acme rod. I wouldn,t trust allthread for this application. The threads are too small and fine , they could strip easily. If all he wanted to do was hold the wall from moving more then allthread will suffice. I imagine he would like to pull the foundation wall as close to straight as possible.
Mike
Thanks, never had heard of it for that applications.
Only seen it in manufactured products and in machinists supply catalogs.
Relax, you don't have to do all that. A foundation has not failed, it may have been skrewed up and only needs to be stabalized. I'll tell you how when I get home tonight.
Gabe
First of all, it doesn't appear, by the information that you have given to date, that your foundation is falling down or apart.
It does appear that the backfilling process put some pressure on the walls however. This is normal but it seems that the owner did not adequately brace the walls prior to backfilling. With wood foundations, it's always advisable to have both the concrete basement floor poured and the first floor framed totally before backfilling.
So what to do now?
If this cottage is older than 5 years, 99% of the settling has already occured and unless you have a driveway against the foundation, no more settling is likely to have a major effect on your foundation.
Stabilization should be the focus.
You could sheet the underside of your joist with 5/8 plywood, thereby creating a waffer panel with your entire floor.
You could install a 2by underneath the joist across the width of your cottage and Diagonally to the center of your back wall.
There's a dozen ways to stabilize but I would need to know all the specifics before making more comments.
I don't know the size of your cottage, whether the basement is finished and I don't know the type of soil or the exterior layout of your lot.
Bottom line..........1 inch off plumb or 1 1/2 inch bowed is not the end of the world and can easily and inexpensively be saved.
Gabe
Gabe,
Thanks for the Good Feedback.
The size of the house is 40' Side to Side, and 32' front to back. Just a rectangle nothing to complicate the shape.
The back fill and surrounding soil is a clay sand mix, with some pretty solid pockets of all clay.
The floor joist run front to back, and there is a center wall which has prevented the side walls from bowing at the center. But, they are bowed between the center wall and the front and back walls on both sides of the house.
Contour around the house is as follows:
Front Wall, Faces North, Backfilled up to within inches of the top of the wall, front yard slopes away at about 1' drop per 10 lineal feet.
Side Walls, Backfilled to same level as front except for last 6 feet where there is a steep drop to the level of the basement floor. My intention is to contour both sides with a gentle slope starting at the front wall and ending at the back wall. (ie: 8' drop along the 32' wall)
Back Wall is fully exposed along the whole length of the wall.
The yard is unfinished and there is no garage yet.
Mike
Typically, most people make the mistake of backfilling wood foundations with native soils that have a significant percentage of organic material (topsoil and grass)that was excavated and piled around the foundation during construction.
Driveways should be located at least 8 ft. from any wood foundations as well.
Drainage of the lot is also important. Making sure that surface water can easily circumvent your house foundation cannot be overstated. If you have a sloping lot and your house is in the middle of it, water is effectively blocked in it's path downhill and will gather against the foundation wall for a longer period saturating the soil. Building swales to divert water away is always recommended.
If it is your intent to excavate around your foundation to change the landscape and slope, you may as well examine the backfill material at the same time to see the quality of the material. If it's all sand, then other than grading I wouldn't do any more than stabilize.
If you're determine to make it right, aesthetics or structural considerations, simple expose the entire perimeter, and use screw jacks to push the walls apart on the sides and then lock em in by adding 2by material across your joists at every 4 ft.
Racking it backwards will be almost the same and you may want to consider adding a dividing wall from the center wall you now have towards the back wall. Sheet the wall with plywood and nothing will move it again.
You don't have a very large house to contend with, no odd shapes, digging around the foundation won't make it flimsy during this process, and you will find that it takes a lot of pressure to push it back. You will have to use a few hydralic jacks for this work.
The biggest force to contend with other than weight is that the lumber has all taken on this shape and will resist any change.
Personally, I don't think it's worth the effort and cost.
Gabe