Main beam sizes?

JRanch · October 20, 2009, 10:40:09 PM

Hello all,
I am new here and love this site. I 've much since I began poking around in here a few weeks ago and became a new member recently.

I have some land in NM that I'm planning to put a 12x16 cabin on with a loft. I will use 10' high walls and drop the loft (bottom of loft floor) down to 7'.

Any way I'm using a pier/beam foundation. would a 6x6 pressure treated beam (2) of them at 10' centers with (5) piers on ech beam be sufficient? Or do I need to go bigger with the beams?

Any and all answers will be appreciated.

Thanks,
Keith

MountainDon · October 20, 2009, 10:58:38 PM

Hi Keith and

fellow NM builder!! Our cabin property is in the Jemez south of the Valles Caldera. Where are you? There's at least one other active NM owner-builder and a few lurkers here.

16 ft long, 5 piers = about 4 ft spacing. A 6x6 on top of those piers should work out fine for what you describe. I'm not an engineer but according to the Southern Pine Council charts that should work.

October 21, 2009, 08:34:16 AM

MountainDon,
Thank you, we have land I just picked up 20 north of Quemado, I'm not quite sure were you are located but I will try to look it up on the map.

I figured it would work (beam size) due to the (5) piers but I didnt check out any charts.

Thanks and I;m sure I will have more questions to follow.

Humbly,
Keith

glenn kangiser · October 21, 2009, 09:01:30 AM

Hi Keith.

to the forum.

John's Little House plans cover that size building - length changes are easy also, and they are very reasonably priced. AYou are not required to have John's plans to post or question here, but I was just thinking that they could help you with a lot of the things you may have questions about.

http://www.jshow.com/y2k/listings/29.html

Bobmarlon · October 21, 2009, 10:18:18 PM

welcome to the forum

October 21, 2009, 10:54:49 PM

Thanks Glenn,
I will keep that in mind.

JRanch · October 21, 2009, 11:29:58 PM

By the way, I have a question for you all, do you think I need to use pressure treated lumber for my floor joists and mudsills?

MountainDon · October 21, 2009, 11:52:17 PM

Depends.

Depends on the distance from the ground. According to most building codes if beams are more than 12 inches above the ground and joists are more than 18 inches above ground, they do not need to be PT wood. In some cases I believe "naturally durable wood" is specified. Those distances are to the lowermost face of the beam or joist.

I'd add that if the subflooring was closer than 18 inches I'd also use PT wood there. I did that on my shed: I used PT plywood for the floor.

So I'd say that if your beams or joists are going to be closer to the ground that those specs, it would be a good idea to use PT wood even if there are no codes or inspections involved. If there is a building code or any framing inspections involved I'd recommend checking with those folks.

JRanch · October 22, 2009, 08:08:20 PM

Don,
Thanks for the info, I will keep all of it in mind. I dont have to go through the inspections or anything like that due to the square footage I am building. But for longevity purposes, PT would be choice lumber to use.

Thanks,
Keith