Question about pouring concrete for wall

[Stihlrunner]

Hi Guys,

I have an old pole barn that has one open side. I would like to enclose that side but the poles are set inside the eaves about 5' and I would like to gain some of that space back. My idea is to pour a concrete footer along that edge appx 12" back from the eave then frame in a 2x6 wall that will support the roof. Then I can remove the poles.

My question is the ground is about 4" of well compacted gravel and it is very dry as the eave has covered it for 20 years. Is it necessary to dig down for the footings or can I form and pour on grade? I am thinking the footer will be about 12" tall x 8" wide, that would work out where I could use 8' lumber since the wall isn't very tall.

Hope this makes sense???

 

[WANNABE1]

I think it depends where you are, but if you live where temps vary such as cold winters etc then I believe you need to be below frost Level or you will have problems when all is said and done, then you will have to redo it all. Which means spending more money then you needed to had you done it right the first time.

 

[KennyG]

This might work but it's risky because you really don't know the stability of the ground. Believe it or not, I've seen 100 year old foundations essentially poured on the surface in cold climates and they were fine, but this is very much the exception. If you are going to pour concrete, get down close to the frost line, or at least a couple of feet if you are in a warm climate. Note that it doesn't all have to be deep. If you use re-bar, you can have a concrete "ground beam" with a series of deep holes every few feet.

If you want to go cheap and easy and you really believe the ground is very stable, don't even worry about the concrete. Get some ground contact treated 6 x 6's, bury them flush with the surface and build on that. If it starts to move over time, jack the trusses up a section at a time and pour a deep footer under it.

 

[Stihlrunner]

Thanks for the advice guys, sounds like I need to do some test digging. I've dug a little around this area and it is hard as heck!

 

[Dr_Zinj]

Measure twice, cut once.

Or

How come we never have time to do it right the first time, but we always have time to do it over?

Dig it out below the frost line. If you don't have frost, make sure you put in a big enough footer that the ground swelling and contracting from rain/drying cycles doesn't heave it all to pieces. California central valley soils can be a monster for that even before you add the shake, rattle, and roll of quakes.

 

[Groo]

how are the joists and rafters coming together? Are you sure the roof will hold up to being supported a couple of feet further out?

 

[chim]

how are the joists and rafters coming together? Are you sure the roof will hold up to being supported a couple of feet further out?

My concern would be that a real structural engineer should evaluate what you plan to do. Several years ago I read through a long writeup in a farm magazine at the in-laws. There were some really bad things that happened to some farm buildings that had modifications done to them. Trusses generally have pretty precise locations suitable for bearing.

 

[KennyG]

My concern would be that a real structural engineer should evaluate what you plan to do. Several years ago I read through a long writeup in a farm magazine at the in-laws. There were some really bad things that happened to some farm buildings that had modifications done to them. Trusses generally have pretty precise locations suitable for bearing.

I assumed that the barn has conventional trusses where the bottom chord is continuous and the truss is symmetrical. If this is the case, moving the support point out to the end will be no problem. After reading the above concern, I realized the trusses could be custom with the overhang designed in. In that case, no change should be made. However, if it is symmetrical it will be fine.