Drafting Help

[Guest 420FLYFISHIN]

im wondering if anyone on the board has any post and beam experience? My inlaws have just purchased a log cabin and they would like to put a second floor on the rear half (front half is on columns and probably should not be over loaded, rear half is on grade)

 

my first question is will we have to enlarge the pads under the center floor beam where a center post will have to be installed or will we have to enlarge all the pads? they are 24x8 right now so about the same size as a 2 story residential strip footing.

 

i will have it cadd and sketchup'ed (have to do it around homework) by the weekend if it helps

[dube]

Without really seeing what you mean it's hard to say but generally I would not point load a strip footing as they are deisgned more for evenly distributed loads such as walls. Pads for posts are generally 36" or 48" square. The 8" thickness is pretty standard.

I have seen thick plate steel laid on pads to help distribute bigs loads on insufficient pads but I'm no engineer so I couldn't really speak about that.

 

Good luck.

[Guest 420FLYFISHIN]

the center floor beam is on pads (2 beforethe grade slopes down) in the rear and then goes to post in the front. no strip footings.

[dube]

Hate to give advice on internet forum but...

 

minimum area for pad supporting columns not spaced more than 3m from bearing is 0.4 sq m. for one floor and 0.75 sq m. for pads supporting not more than 2 floors. So that would be 24" square for single floor which sounds like what you have and 36" square for what you need.

Other things to consider would be whether or not the columns will stack up on eachother or will the upper point load come down somewhere midspan of the beam below in which case the loads would have to be factored into the existing lower beam as well.

 

hope this helps. concrete must have been expensive when they built the place

[Guest 420FLYFISHIN]

that is an excelent idea, 2 post plus wall suport instead of a single point in the middel. it has 8 pads under the rear section of the floor. columns will have to fall onto the floor beam (8" log to pad)(would this be a grade beam at this point?)

 

is there a code book for post and beam or does it just fall under provincial/national code?

[dube]

Not sure about timber /log homes having exclusive code. The Alberta building code is the last word and also the minimum. I would imagine logs and timbers would be designated by dimension not unlike regular framing material. May be able to find span or load tables specific to timber building. I have to admit all of my timberframing experience has been off the grid in the backcountry, permits and inspections not part of the picture.

[Guest 420FLYFISHIN]

i want to do this as best as possible because it will be mine and my wifes in the future. but if we have to lift the cabin to replace all the pads i will try to sell them in a small cabin to the side on a pad