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General => General Forum => Topic started by: peteh2833 on May 08, 2007, 04:14:41 PM

Title: Help on laying out post and piers
Post by: peteh2833 on May 08, 2007, 04:14:41 PM
I'm building the 20x30 1.5 story right beside a 1 story 20x30 cabin in the north central mountains of PA. I will probably use the post and pier foundation. I was considering the poured footer and crawl space foundation. If I go with the post and pier I can do most of the work my self and get a concrete truck. If I go with the other I would have to sub it out. My 2 questions are:

1. Would you go with the post and pier?
2. If I go with the post and pier what is the best way to lay out where I drill the holes? Can I just measure of the existing camp and then go from there? Thanks for the help in advance. Pete
Title: Re: Help on laying out post and piers
Post by: n74tg on May 08, 2007, 07:57:55 PM
Depending on how big your girders are (floor joists sit on girders) and how much deflection you are comfortable with (or how much the inspection authorities will allow you to have); that will determine how close your piers have to be.  I'm thinking probably no farther than ten foot spacing, but maybe closer.

Don't the 20x30 plans come with a recommended foundation plan?
Title: Re: Help on laying out post and piers
Post by: n74tg on May 08, 2007, 10:16:53 PM
If the plans don't come with recommended foundation info, here's an article that may help.

http://www.umass.edu/bmatwt/publications/articles/calculating_loads_on_headers_and_beams.html

And here's another:

http://www.umass.edu/bmatwt/publications/articles/sizing_engineered_beams_headers.html

In fact, that website has a LOT of valuable information.  And if you can get yourself a copy of "Residential Structure and Framing" from the editors of The Journal of Light Construction there is a good article in there beginning on page 17.  ISBN 0-9632268-8-6
Title: Re: Help on laying out post and piers
Post by: glenn-k on May 08, 2007, 10:27:40 PM
Layout should be in the plans.  Just decide where your building line is going to be and - yess - if you want to attach it to another bldg, square it off of it.  Leave enough room to work and decide your method of connecting the two before you start- floors walls - roofs - flashings - elevation problems - interference etc.  Might even be good to put it a couple feet away then fill in the section between the two - like one stud spacing.  

Ultimately, you are the only one who knows exactly what all is going to need to happen there, but we will help with what we can.  

If you need changes for the plans locally for permits - etc, your architect will be able to help with connecting the two.  If no requirements - permits etc. , you just have to do what is necessary to make it work safely and look good.
Title: Re: Help on laying out post and piers
Post by: jraabe on May 09, 2007, 09:01:12 AM
Yes, use the foundation plan of for the 1.5 - 20' wide. You have both the crawlspace and the post and pier foundation plans. Use that layout for the piers and beams.

Where the two projects join, the party wall, you will want to have a beam or doubled joists and make sure you are not overloading the piers with loads from the other building. This depends on how the other building is constructed. If in doubt, add an extra pier.
Title: Re: Help on laying out post and piers
Post by: peteh2833 on May 09, 2007, 11:06:35 AM
I have the plans and understand them. Just wanted to know which is best between the 2 and what is the best way to lay out where to drill the holes? Meaning how to make it square. How big should I make the holes/ diameter? Also if I use engineered joists, do I need a center girder? Thanks Pete

PS I plan on building it right next to the existing camp and leaving a space of about 2-3 feet between them. After it is finished I plan on connecting the two camps with a breeze way.
Title: Re: Help on laying out post and piers
Post by: PA-Builder on May 09, 2007, 05:18:38 PM
Peteh,
Most insurance companies in PA don't like recreational cabins, and some don't like post & beam construction.  If you are planning on insuring your cabin, you may want to touch base with your insuarance agent.  
Title: Re: Help on laying out post and piers
Post by: peteh2833 on May 09, 2007, 07:03:43 PM
Ya, I know. I have insurance on the one there now. How expensive is it to pour a footer and a wall for just a crawl space foundation.? Pete
Title: Re: Help on laying out post and piers
Post by: PA-Builder on May 09, 2007, 08:06:13 PM
I paid three men around $1800 (labor only) to lay a 26' x 28' basement wall (10" blocks, 11 course high) in 2003 in south-central PA.  I had already put the footer in,  and I supplied all blocks & mortar.  Your footer should run $400-$500 for concrete plus a couple hours labor, if you do the form work.  
Title: Re: Help on laying out post and piers
Post by: youngins on May 09, 2007, 09:21:06 PM
Quote...what is the best way to lay out where to drill the holes? Meaning how to make it square. How big should I make the holes/ diameter?


I had my pier position down to 1/4" accuracy before digging.  After my neighbor and I dug the holes with the auger, we ended up WAY off.  (Wendy is still giving me heck - she says she can't leave me alone to do anything.)

I dug bigger holes, and and still think I am off on a couple of them.  I have a city garbage bin packed full of dirt that I cannot event move.  :'(

(https://i147.photobucket.com/albums/r288/quitesweet/Building/Playhouse/P1010017.jpg)

For the "BIG" project, I think I will go with  a backhoe - dig two trenches twice as wide as I think I need them and then go from there.
Title: Re: Help on laying out post and piers
Post by: peteh2833 on May 10, 2007, 08:30:26 AM
Thanks for the info. Pete
Title: Re: Help on laying out post and piers
Post by: Amanda_931 on May 14, 2007, 09:13:45 PM
You also don't want me to lay out anything that is supposed to have right angles in it.  For you or me either.

:'(
Title: Re: Help on laying out post and piers
Post by: glenn kangiser on May 15, 2007, 12:50:29 AM
3,4,5 or 6,8,10 or 30, 40, 50   or multiples thereof, Amanda--- no problem. :)

Leaving things loose if possible cross square diagonally by measuring corner to corner then tapping it square with a hammer until both readings are the same.

If you find it difficult to move the framing diagonally, get a bigger hammer. :)
Title: Re: Help on laying out post and piers
Post by: Amanda_931 on May 15, 2007, 10:19:58 PM
I know the math, but....

The gal who was (is? not sure) working for me has gradually going into the manic end of bipolar.  Maybe she was the problem all along.  ::)

I don't have problems with quilts.  Even quilts with a lot of patches in them.  But....  
Title: Re: Help on laying out post and piers
Post by: peteh2833 on May 17, 2007, 09:10:44 AM
Anyone have a suggestion on how big the holes should be for the post and piers? Also, deep for north central PA? Thanks Pete
Title: Re: Help on laying out post and piers
Post by: youngins on May 17, 2007, 10:15:01 AM
Frost depth you can get probably by anonymously calling local public servants. I am not sure if the IRC has a table on that.

For 12" dia" tubes, maybe one and a half twice that size - you'll find you'll need the extra room - dont ask me how I know ::)