I'm planning on building the house in the Jack Sobon book Build a Classic Timber Frame House. I really want to build a dry stack stone foundation. I live in northeast Texas, and my frostline is only 1 foot deep. I was thinking of going to the frostline and coming up 18 inches above the ground. Our ground around here is about 4 inches topsoil, 6 inches sand/clay/gravel, and then 4 and a half feet of hard red clay. I have read the stone foundation post on this site and read all the pros and cons of dry stone foundations. In my climate of very little freeze heaving, what would be the drawbacks of using a dry stack stone foundation? I don't want to use a concreted stone foundation because I want lots of ventilation under the house to counter the high humidity in our area. Most older houses in this area were built on a pier and beam foundation, and most new ones are on a concrete slab.
Shad,
In my opinion, loose stone is exactly that...loose. I understand you wanting to vent because of the high humidity, but I feel that the prevailing winds might want to slowly push the building and cause the loose wall to shift and possible break up over time. What if you built mortared stone piers/ columns resting on larger poured concrete pads below frost line and hidden from view, under the sill beam load points? It would be less material, less time, more ventilation, easier to keep piers at the same elevation, you could anchor the building to the pier, and it would look appropriate for the timber-framed house you are building.
I'm just sayin'..
Good luck ;)
Rooster
Shad,
How big a footprint are you thinking? Would you use sono tube posts to take the load in between?
If you are or you know some one who is an accomplished stone wall builder and are using capstones I say go for it. Lots of houses up my way in snow-country are 200+ years old on fieldstone foundations and sure, some have settled more than others, but if yours lasts 1/4 as long it won't be your problem.
If you are building your house on a pile of rocks though, Rooster might be onto something.
Hey thanks for the replies. Yea, I had considered making some concrete piers like the ones in Ted Benson's second book and filling in between those with dry stack stone just to keep the dogs and cats out of the crawl space. I played with stacking some rock yesterday and really liked it. It's nice working with a natural materal like stone. I'm not crazy about working with concrete but I can do it if I have to.
Shad
The foot print is 18 x 36.
We, the general public, have used loose stone foundations longer than concrete. If you feel competent go ahead with it. It will need minor attention on a regular basis that should be part of the experience. Glad to hear other are moving forward with this gone by technology. If you do use mortar look into a lime based mortar. Do you have a good supply of rock? What shape is it, flat?
Tim
well i was thinking of using rip-rap. the highway dept uses it to stop errosion. it comes in all sizes from around 24" down to 1/4". they quarry it in Arkansas not far from here. it's a dark grey color, i think granite. Last time i checked it cost around $20.00 a ton. Some of it is flat, some irregular shaped.
Moonhill, what type of minor attention were you refering to?
Hey,
Remember 3 things:
#1 Cats hunt mice.
#2 Rat Terriers hunt rats.
#3 Both Rats and Mice will find a way through the loose rock foundation, and live under "the house that Shad built". ;)
This thread is begining to get interesting! 8)
Rooster
The minor attention is chinking here and there, just a quick walk around, visual inspection. The reason stone foundations fail is many years of neglect. Being a timbered building you could remove a whole section of rock and put it back in place with no effect on the building, not that, that is what you would have to do, just to point out that it all works as a unit. It has the flexibility to give.
Read more on the subject and find a local stone worker for more input.
I have concrete walls in my basement, a vapor barrier, foam insulation that has strapping nailed to the concrete wall, then drywall. We had mice living in the cavity, I am guessing between the strapping and drywall. Cats were the solution, 7 to be exact. So no matter what your foundation is like you are likely to have rodent issues. Leave a hole big enough for the cats to get into, or maybe not, they also have bad habits.
Tim
My other concern about the dry stone foundation is resale value. I plan to live in this house forever but if that changes and I have to sell it, I 'm wondering how much trouble I'll have convincing a buyer that this is a sound foundation? or a house inspector thats never seen a real stone foundation.
(https://forestryforum.com/gallery/albums/userpics/10186/DSC01825f.JPG)
(https://forestryforum.com/gallery/albums/userpics/10186/Picture_849.jpg)
Shad,
Your concern over resale value is legit, but it appears there is always someone who will lend (even today) on things like mobile homes, strawbales, rammed earth, etc, so I wouldn't be overly concerned about it.
That said, I would practice a small foundation or stone wall fire pit or something out of rip rap and see how it looks and stays together. My neighbor went to the library and has been building some impressive stone walls around his place for the past few years. Nice architectural features, but I can say he has developed his skill. He is comtemplating reworking some of his earlier walls, which look fine in their own right, because the look sloppy compared to his new stuff.
If your initial experiments can be relativly level and stays together you are onto something. A concrete "bonding beam" poured along the top and running hardware cloth around the inside would probably address most concerns, including using less concrete, but then so would sonotube posts for less $ and effort.
If you are content jumping on the "green" bandwagon, it could be worth more than a conventional built wall.
Practice makes perfect.
Tim
Well I got the photos in the other day but a customer came in and I have not been back to it.
Packed crushed stone gets almost as hard as concrete and in some ways is better. If you are talking about the stone from here it is limestone. Here we use 4" thick block and then do a "dry stack" which means the rocks have mortor on the back side sticking them to the block. In true wall form they are over 2 ft thick with small stones poured in the middle.
(https://forestryforum.com/gallery/albums/userpics/10186/DSC01653f.JPG)
After you stack stones for a while you will get an "eye" for it and it goes faster. Start in the middle of a long wall so that by the time you get to the corner you will have learned a bit because you do not want your corners weak.
We like photos if you deciede to build it.
Hey thanks for the pictures ARKANSAWYER. So you're saying the true stone walls up there are usually two feet thick? I was thinking of going down a foot deep to the frost line and making the base layer of rock 2 feet wide then tapering up to about 16" at the top. Or filling the 2' wide 1' deep trench with crushed and tamped rock and starting at ground level with a 16" thick wall 18" high. I planned to use alot of wide rocks to span the 16".
The good thing about it being a crawl space is that I can keep it kind of flat and uniform on the outside but it can be jagged on the inside and no one will see except the cats and mice.