Building a Timber Framed House on Dry Stack Foundation

Hello,

First post ever.

I am planning to build a timber framed house on top of a 10' dry stacked wall. Which will sit ontop of a approximate 3' deep by 5' wide river rock gravel  footer trench. The footer trench will travel around the edge of the house at varying slopes to drain water out through a gravel floor of a tunnel. We are digging down 4' before we dig the footer as to leave 6' of basements exposed to later mound dirt on the side about 3' up. The house  foot print is 66'x 44' it will have a barn like architecture. I plan to set sill right on top of rock wall and let gravity hold. The house. Since I figure a house comprised of massive 8"x 8" beams of wood will be pretty hard to shift.

My main reason for posting is to get ideas for building the footer. I would prefer to be as natural and cheap as possible but dont know if there is a better solution for keeping particulates out of my gravel footer.
 My first plan was to carve out footer then lay landscaping paper followed by pvc pipe with holes then pour river rock gravel ontop of that approximately 3' deep x 5' wide then enclose that with the landscaping paper like an envelope.
 I understand this would be the typical way to build a french drain, but I would like to explore not having to use the landscaping paper and pvc pipe but need to keep particulates out of my gravel for free flow drainage.
 Past the soil line my location sits on red clay. I was wondering if it would be practical and work to dig the trench and then build a fire all throughout the trench and fire the clay like pottery. Although im not sure how long that could hold out moisture from the surrounding hydrological pressure.
 I would like to figure out how to not use these two items since primarily i want to build a structure that stands a long test of time and want to cut out as many artificial and quick perishing items as i can. I would like to build a house that the bones and foundation have a chance to survive for hundreds of years. If anybody has any ideas without concrete or artificial materials im all ears.

Thank you permies,
Joe Koller

Hi Joe, welcome to Permies!

I like your idea, and I will disclose that I am not an engineer. Where abouts are you located? Are in you an area with any seismic risks? I think the dry stack stone will work. The footing however, I believe could be challenging to get it right to avoid possible future problems. You mentioned clay soil, and clay soils are expansive, some more than others. It's this expansion and contraction that can cause minor to major problems in conventional homes such as cracked foundations, cracks in brick work (like the stair stepping cracks going up walls and corners), cracks in interior sheetrock walls, doors that once closed no longer close, etc. All of those are symptoms of foundation movement, either from a poorly constructed foundations, expansive soils, or freezing and thawing. I have a few ideas that may help you in your quest.

-Check out the USDA web soil survey found here: https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm In it, you can zoom in the map, click the AOI button to draw an Area of Interest around your building site, and then click the tabs across the top to view soil information. In it, you'll find oodles of information, like the name of the soil, expansive qualities, how well it drains, thicknesses of the horizons (layers), depths to obstructions (like bedrock), and more. This will have information on how little or bad the soils expansiveness.

-Expansive soils can be managed by backfilling a foundation with crushed limestone, like #57 for example which has the fines removed. This type of gravel readily moves with each stone slipping by its neighbor and will act as a shock absorber, allowing the soil to move and help reduce or possibly eliminate lateral compression stresses on the foundation wall. The worst of the highly expansive soils can exert a compressive force of a million pounds per square foot. It may only push a fraction of an inch, but they can push hard.

-Gently slope the footing trench so water all runs one direction to some exit.

-Fill your footing trench with river rock 6 inches at a time, and run a plate compactor over each layer.

-Try to incorporate some sort of french drain around the footing.

-Slope the finished soil grade away from the home in all directions to help reduce the amount of rain that infiltrates the soil around the house and heads down towards the foundation and footing.

-And lastly, consider installing jacks between the sill plate and your subfloor. This can make it relatively easy to lift and re-level portions (or the entire dwelling) if the foundation settles in areas.

I'm not familiar with the use of a non-monolithic rigid footing to build on, but that doesn't mean it can't be done. Others may have experience in this area and have better advice. Hope this helps!

Your foundation will be fine, millions of houses in the northeast are sitting on stone foundations as they are called, and survive just fine to this day. My other home sits on a rock foundation, and not only has it not moved in the 90 years of its existence (the previous house burned so for New England, 90 years is a very young home), it has solid sills. They are original, and have not even begun to rot, but dry wood does not rot.

Welcome Joe!  Hope you post the pictures of your build - would love to do the same at some point.

> [lose the pvc]
"Drain tile", ie. clay drain pipe in 18" sections with bell&spigot joints (NOT the rubber sleeve type joints), lives forever, provided: 1) it's set in soil that never moves much; 2) the back fill around and above it is sufficient to bear the loads applied above it (don't bury it under 12" of sand and then drive the dump truck over it...). The joints between the sections, uncaulked, provide water ingress into the drain pipe.

> filter fabric
"Concrete sand" and graded gravel have long been used by dam designers and road builders to provide filtering so that the necessary drains do not clog with sediment. It will take some research, I'm afraid to translate the technical literature unless you can find some engineering forums where somebody will explain it in plain English. It's not complicated in concept, but the specs's are given with equations and jargon. Besides, the net, you might contact various highway departments, large and small,  and see if you can find an engineer who'd be willing to talk to your about what they do locally as filters for a drain. Hit/miss, I'm afraid. But this is old tech that has proven to work well. It's just not talked about much because who wants to listen to engineering jargon? It might even be "cheap", depending on what material you find close to you.

Here is the search term I cobbled up to get a quick look at available info:
     "concrete sand" drainage sediment fines boundary

And here is an example of one of the papers:
http://oilandgas.ohiodnr.gov/portals/oilgas/pdf/stormwater/RLD_11-6-14All.pdf


Cheers,
Rufus

> compactor...

It's my understanding that a big "jumping jack" works faster and deeper than plate compactors.


Rufus