24 x 30 Pier & Beam Question

[daybreakhuntin]

Live in rural Arkansas and dreaming about a future cabin....Thanks for the help


If I build a 24 x 30 using peir(concrete blocks) and beam (6x6) would I be better off having 4 beams on an 8ft span using 2 x 6 or 2 x 8 as floor joists. OR  Build using 3 beams on 12 ft span and use 2x10 or 2x12. Trying to stay as cost efficent as possible.

[John_C]

According to my Yellow Pine span tables even a No.2  2x8 would span 12'.  Also keep in mind that your actual span will be a bit less than 12'  with 3 beams (12ft. - outside overhang if any, width over outer beam and 1/2 width of center beam).

That said I'd still go to 2x10 for added insulation and a more rigid floor.YMMV

[MountainDon]

First I'd like to ask about your overall plan. Single story? Upstairs or a loft only?

Then a question about the beams. How was the 6x6 size arrived at and what is the spacing of the piers you plan to use?

Once past that I'd agree with John C on the joists. 2x8's supported on three beams would be getting towards the maximum span allowed. It's not usually good building practice to push the limits. What do you plan for the finish flooring? 2x8 would not be sufficient for ceramic tile for example. 2x10 floor joists at 16" OC would be stiffer and would be required for ceramic tile. 2x10 would also allow for better insulation as John pointed out.

Those are my thoughts. G/L on the dreaming... I've done a lot of it myself.

[daybreakhuntin]

Since we are dreaming here....

I want to build a hunting cabin to use on the weekends and as a family retreat, nothing fancy, use wood stove as heat source and try to keep building costs down. Again this is not going to be a retirement home or permanent residence.

Plan is for 10 ft side walls with a loft, used only as a sleeping area with bunks on one end, bedroom and bathroom/mudroom underneath loft area.

Beams will probaly be logged from trees we cut down. 

We like the look of using natural stone as piers, we would probably acheive this by using concrete blocks as the piers and covering in stone at a later date. It seems the logcial thing to do would be to use 3 beams spaned 12ft. We would space the peirs every 6 ft.  Probably would use 2x10s as joists.

Subfloors- Again I would like to stay cost efficent (is that better to say than cheap)..
What would be a good subfloor to put down. OSB, Tounge and groove Plywood ?
How would 1 x cedar do as the finished floor?

Insulation- Can you get away with no insulation in the floor. I know this is not the standard practice, but again cost efficent?? ANY HELP HERE???


Exterior- Would love to do 1x12 board and batten with a green metal roof.

Again all these are just dreams but then again dreaming about it is half the fun.....

[MountainDon]

Let's go back to the beginning and ask one more vital question. Is the area you are going to build in covered by building and /or other regulations? Is there any need to meet local code requirements or are you totally free to do as you wish? The answers to that question may be substantially different if you are subject to some rules. If in doubt ask first so at least you know what you could run into.

Then let's go from there. 

[daybreakhuntin]

No codes or permits required, building in the backwoods of Arkansas.....

[MountainDon]

Alright then!

Then the thing is to make something that won't fall down, will be weathertight and doesn't break your bank.

Do you know of a sawmill in your area? If there is you could see about having them saw some of your trees into the timbers you need. Ditto the boards needed to so board and batten siding. Or a sawmill of ypur owm?? There are several members here with their own mills.

Starting at ground level...

I don't know Arkansas... does your area have much frost to worry about? Ground freezing to below your foundation footing depth will cause problems sooner or later. So the first design point, after settling on the length, width and height of the cabin, would be the footings and foundation.

You mentioned desiring a natural rock appearance for piers. I'm in favor of using concrete blocks on a pad footing as you describe. That may be easier to level out, than simply using the available rock and mortaring them in place.

Beams will probably be logged from trees we cut down.

Do you mean using the debarked trees as cut, or having the tress sawn into timbers? If you mean the trees without sawing square or at least two flats 9top & bottom) you may have troubles getting everything level. You want to try to get the top surfaces of the beams level to within 1/8 inch, no more than a 1/4 difference at the very worst. Otherwise everything you do from there on, as you build upwards will be more of a problem.

And for my own curiosity, how big are your trees; diameter, height? I have lots of trees but not too many larger than 10 to 12 inch diameter. Tall enough though, 50+ feet. Everything grows so slow in the heights of the NM mountains.

Others here will hopefully have ideas about using the materials at hand.