Wood Foundations and Ground Water

[milkman636]

My wife and I have been in the market for a larger house for a while now. A nice one has come up for sale near us that has the bedroom space that we need and a nice parcel of ground, but it has a wood foundation. The basement floor would be at least 6' below grade at the front, and the grade tapers around toward the back of the house so it ends up being more of a daylight type basement somewhere around 4' below grade along the back. The basement walls are almost 100% drywalled and finished.

The house was built in 1997 and everything about the place looks like they didn't cut any corners. The materials, finish, and workmanship all look very good. The owners are the original ones that had it built. The husband died and the wife is selling it. The house sits way back about 1500' off the road in what used to be a farm field. The neighboring field is freshly tilled and is a typical loam soil. Grade is slightly sloped away from the house but then flattens out for 100's of feet around it. Its the type of setting where I would expect mud to be an issue in the spring.

The basement is dry with no visible signs of wetness and no musty smell at all. But it is also fall, not spring when its raining and the ground is thawing. I'm always concerned about groundwater, but because of unfamiliarity with wood foundations I am more concerned than normal. My wife wants to buy the place, but I need to know more about wood foundations. So does anyone out there have any insight for me on how they are constructed and what to look for?

I'm accustomed to our current home that is on the highest spot along our road, and our basement is bone dry and doesn't have a sump pump or even a crock for one. Am I being over-concerned about ground water issues?

 

[Sodo]

My home's foundation is wood posts, sitting on pierblocks. House is 87 years old and no problems with the wood foundation, its all straight. New half of the house is on a modern foundation.

Have a sump pump in a well below the basement floor, I actually have two pumps in there, one above the other, as a backup. I am on the highest spot in the neighborhood on a ridgetop. Land drops down in front and in back of the house and I'm a foot or so higher than either of my adjacent ridge neighbors. It's actually quite puzzling why I'd need a sump pump but it runs often. Of course the basement is below grade though, buts still puzzling where all the water could come from.

Not sure if that helps in your question, looks like your just gathering info?

 

[milkman636]

Yeah, I've seen old houses with split trees for beams resting on piers, so I know wood can last a long time. This is really the first time I've looked at a house with dimensional wood walls and plywood sheathing below ground instead of block or poured concrete. Like anything new its always a little scary. If its good, why aren't more people doing it? And if its bad I want to know before I go any further. Or maybe it is the best thing since sliced bread and word hasn't gotten out yet?

I am banking that there might be a few guys on here that have done it or know something about it. Seems like this group collectively knows something about everything.

 

[Sodo]

Well being 87 years old it's old growth douglas fir, which is pretty rot-resistant. If 'your' posts are some kind of softwood pine it might not fare so well.

Can get good info on TBN, but theres lots of guessing too and can be difficult to sniff out what's a guess - they tend to back up guesses pretty well. I doubt wood foundation is better in any way except more economical and faster to build which were not trivial reasons back in the day when folks weren't as wealthy as today. But it's no longer allowed in the code.

 

[MossRoad]

My wife and I have been in the market for a larger house for a while now. A nice one has come up for sale near us that has the bedroom space that we need and a nice parcel of ground, but it has a wood foundation. The basement floor would be at least 6' below grade at the front, and the grade tapers around toward the back of the house so it ends up being more of a daylight type basement somewhere around 4' below grade along the back. The basement walls are almost 100% drywalled and finished.

The house was built in 1997 and everything about the place looks like they didn't cut any corners. The materials, finish, and workmanship all look very good. The owners are the original ones that had it built. The husband died and the wife is selling it. The house sits way back about 1500' off the road in what used to be a farm field. The neighboring field is freshly tilled and is a typical loam soil. Grade is slightly sloped away from the house but then flattens out for 100's of feet around it. Its the type of setting where I would expect mud to be an issue in the spring.

The basement is dry with no visible signs of wetness and no musty smell at all. But it is also fall, not spring when its raining and the ground is thawing. I'm always concerned about groundwater, but because of unfamiliarity with wood foundations I am more concerned than normal. My wife wants to buy the place, but I need to know more about wood foundations. So does anyone out there have any insight for me on how they are constructed and what to look for?

I'm accustomed to our current home that is on the highest spot along our road, and our basement is bone dry and doesn't have a sump pump or even a crock for one. Am I being over-concerned about ground water issues?

No, you are not being over-concerned. This is probably the biggest purchase of your life, so be concerned.
My father was an architect and construction specification writer. He was fascinated with new building technologies. I remember watching a show with him about a house with a permanent wood foundation. He said they are O.K. in some applications, however, he would never use one. Too many things to go wrong. Moisture, frost, freeze, insects, ground water, rot, improper installation, etc... are all real concerns. In a nutshell, Roman concrete is still standing 2000 years later. :confused3:

If I were you I'd contact some sort of building inspector, engineer, that sort of person, with some knowledge on the subject and ask them how those things hold up in your area. Also, see if you can find any of the original plans at the local building department. See if you can find any drainage plans. Look for ground water maps. Soil maps. Topographic maps. See if you can locate the original builder. See if the owner knows why they chose a wood foundation. Maybe it was purely on price. Sounds like a nice place, but do your homework. To get it replaced, you'd have to jack up the house, remove the foundation, pour a new one and set the house back down on it. Not cheap. Good luck. I hope it works out for you. :thumbsup: Also, look for transferrable warranties from the builder/manufacturer of the wall system.

 

[TCowner]

I have the wood foundation in my house that was built in 1989. I was a little skeptical at first but would not hesitate to build/purchase another. The wood foundation manufactures are quite demanding in their installation program. The key element in their program is to move water away from the foundation. I was quite amazed at the amount of pea rock and drainage tiles that were used below and around the foundation. In 25 years we have not had any water leakage issues in the basement and during this period we had some very wet springs and some very heavy rainfalls.

If a foundation is going to take on water it would mine. The soil here is made up of about 1 foot of black dirt, then 6 feet of clay and limestone followed by solid limestone. Needless to say, its holds moisture.

The obvious question is what happens 50 years from now, or a 100 years from now. I won't be around to answer the question. But when you hear about problems that traditional block and poured concrete foundations have then this system has as good of chance of long term survival in my opinion.

 

[newbury]

Well since the OP doesn't describe either the wood or his location (

Palm of the Right Hand

MI? AK?) it's difficult to make a good comment. We need more info -

What's the wood contacting the GROUND? Old growth Doug fir? Cedar? SYP? Cypress?

What's the climate? Southern Florida? Arizona? Alaska?

In one of my "neck of the woods" (MS) almost any wood except Cypress would be subject to termite feasting. In northern Vermont spruce might be OK. But unless wood basements are a common practice in the OP's area (ask several real estate agents) I'd steer clear.

 

[mfreund]

Time for a local building inspector. We had a whole house inspection done and would not buy a house with out one. When we bought our house the $600 inspection got us a $10000 dollar roof.

 

[farmer2009]

There are a few wood basement houses around here. My grandfather build several of them back in the 50's. They are wood that is then layered with a tar like water proofer and sometimes a mesh or plastic. The key is the exterior weeping system. He always ran pipe at two different levels and has gravel fill and filter fabric around them. They didn't leak then and to my knowledge and his they still don't. If the outside weeping is done right there is no need for an interior weeper.

Find the drain outlets and have a plumber run a camera all the way through the loop. Also try to determine if the pipe is at or below the grade of the basement.

Then take a shovel and dig below grade won't take much to see what kind of water proofing was used. Also find the interior sump pump pit.

 

[dave1949]

I've only seen one constructed, around 1980, NW Ohio.

They dug out for a basement as normal, then put down pea gravel and leveled it. The basement walls were built like a standard wood framed wall using treated lumber and treated plywood sheathing. Those were set directly on the pea gravel, just like setting a wall on a sub-floor. I don't know any drainage details.

I have no idea how it worked out since we left the area in 1985.

The problem with anything non-standard in housing is, whether it is perfectly fine or not, the market has skepticism, as you do. It was cheaper and faster to build, it should be priced as such. You would be taking on the ownership of that market skepticism.

 

[milkman636]

Its in MI. The wood used is dimensional pressure treated pine. I looked at the USDA soil survey may and the soil is classified as Capac Loam.

You guys have made some good points so far. Roman concrete is still around, but I also remember seeing a documnetry that said Venice was built on wooden piers sunk into a swamp. Dave has a good point about skepticism in future buyers if I were to sell the place in the future. He is thinking a little farther ahead than I was.

TCrowner sounds like he is living in a wood foundation in similar soil, and happy about it. And I have seen some cracked and wet masonary foundations. One I looked at last week had water along the base of the wall in a 2002 built walkout basement that should have had the grade working to help it.

Normally I would run away from anything that looks questionable, like MossRoad suggests, but what gets me about this place is that even though the guy is dead, its easy to see he was meticulous in every detail. I am guessing he worked in the electrical field in some capacity. The wiring, panels, sub panels, and even an exterior service disconnect at the meter socket are all done very neatly with every wire labeled. Outlets and switches in everyplace you could want. There is even door contact switches that turn on the lights when you open the closet doors. The heating and A/c are top of the line with zoning. There is an air to air heat exchanger for the exhaust fans. The well tank is huge, kitchen has built in wall ovens, the windows and doorwalls are high line Andersons. Rooms are all generously sized, and all the trim is good quality. The roof is original and looks in great shape. The barn is two story with a walk out deck on the second flloor, And he has nice built up work benches and shelving. Everything I see says he wasn't cheap skate. I wish I could ask him why he chose a wood foundation.

I do like the idea of asking who the builder was and seeing if I can talk to them. Home inspectors never have impressed me.

 

[Sodo]

The problem with anything non-standard in housing is, whether it is perfectly fine or not, the market has skepticism, as you do. It was cheaper and faster to build, it should be priced as such. You would be taking on the ownership of that market skepticism.

Good point. Try to find a "standard" house inspector, that's "local". He will tell you first of all, what he's seen in other houses in the area, and how they've fared. And furthermore, you will find out what the local inspectors tell other buyers, which if you sell, you need to know. If he's a busy inspector, and he sees lots of _____ foundations, he will be able to tell you if they work ______ in your area.

The house you want, and the location you want, and the price you can afford, and the schedule, are far more difficult than inspection. Inspection is about the cheapest and most expedient part of the process, just hope you find an inspector who's experienced and practical. Agreed some home inspectors are hacks, you need referral. And not from a real estate agent, those referrals are geared toward keeping the sale moving ahead. Anyway it sounds like you can do a lot of the inspection, and capable to evaluate, or second-guess your inspector's comments.

 

[doxford jim]

I can tell you that a lot of houses in my area have been built with treated wood foundations. The chemicals do not stop rotting - of which there are numerous causes.
I know of four families that have had to remedy the rotting foundations with concrete - an expensive process as well as a lengthy process. It can be done using a good contractor.
I guess it boils down to what you want and how badly you want the property.
Inspectors are easy to find. Getting just one opinion doesn't do much for you. Perhaps contacting architects or civil engineers might help, but the bottom line is the foundation is wood and will be prone to rotting or insect damage eventually.
My take is that your wife has fallen in love with the property and that goes against any rational decision making.
From my limited experience on buying houses is to give this property a failing grade. When in doubt walk away - there is nothing you can do if you buy it and the worst happens, except kick yourself hard and get the check book out.
There will be plenty of other places for sale and you will get what you want without the uncertainty and worry of a possible foundation failure.
Just my two cents. I hope you make the right decision.

 

[mfreund]

With a inspection report it gives you leverage to reflect the cost of replacing the foundation in the offer of the price.

 

[HEC]

One concern I would have is resale , my neighbor has a wood foundation and the house has been on the market for over 2 years , can't find a buyer and it is a nice home on a very nice piece of ground .

 

[jdzaya]

My wife and I looked at a house with a wood foundation last summer. The land all around the house was pretty flat the exception being the location of the house, it was built on a big pile of fill dirt and sand. The wood foundation was heaving and buckling in various parts of the basement which was finished. The house and property were absolutely gorgeous!! When I read your post I thought you were looking at the house I looked at:laughing: In my opinion, the house I looked at, the foundation was not properly installed. I have only seen one other house with a wood foundation too new to know what will happen with it. Not having a sump pit in my area would worry me. Like the others have said, do your research and don't buy it on emotion

 

[milkman636]

Thanks everyone for your input, you've helped to solidify a decision. I am going to forget about this place and move on. The biggest factor for me is future resale-ability. Right now it's a 17 year old wood foundation system. In 30 yrs it'll be a 47 year old wood foundation. By then, time will have had alot more opportunity to work on anything that wasn't done just right. And wood will not stand up to the challenge as well as concrete. It scares me a little, and I'm sure it would affect a future buyer's impression of value. You guys hit the nail right on the head for me.

My wife is not going to be happy about this, but that discussion would be best saved for another thread. We have 8 kids and she really wants to stay in the same school district, and keep all of our service providers like doctor and dentist and such. That makes our pool of potential homes smaller.

 

[Sodo]

Be careful about Forum advice. It is often skewed from the viewpoint of someone who has not SEEN the subject at hand. It often chooses to err on the side of caution, and frequently, extreme caution. And when fear of the unknown turns out to be unfounded then it's just "oh well, didn't want you to get stuck with a lemon,,,,". They do want to help but they're assuming an unlimited supply of suitable homes and that your wifes happiness is trivial. Its not.

Anyway you seem observant and capable. Foundation problems can be insurmountable for some, and solvable for others. Consequently one guy says buy and the other says walk away. And its quite possible that there are things an observant guy can do now to eliminate future problems.

Good luck. Moving is both disruptive and exciting, makes you push the reset button.

 

[farmer2009]

Even with a concrete basement you have to pay attention to the construction of it. Poured concrete and concrete block foundations seep and crack. They don't last any longer than any other material if not protected and built properly. Your water proofing is drainage is your key.

 

[dave1949]

I think you made the right choice.

There is no comparison of the costs of fixing a wet concrete basement and jacking up a house and replacing the wood foundation. Since both are potential risks, the less $$$ risky choice is the concrete. We can't eliminate risks but we can sure compare them.

A concrete foundation that is 10 years old and in good shape has a much better chance of still being in good shape 25-30 later than a wood foundation IMHO. Even if you had to dig up and replace the footer drain around a concrete foundation that is minor compared to jacking a house and building a foundation below it. Not to mention the house would not likely be livable for several weeks once it is jacked up.

EDIT add: What would make sense if you really want the property, is to buy it for $20K to $30K less than a comparable property in your area. Then hope for the best but be prepared for the worst. Risks have a value.