Help with Flooring Suggestions

Reply

  #1  
Old 03-10-04, 04:13 PM
R
Member
Thread Starter
Join Date: Jan 2003
Location: CT
Posts: 206
Received 0 Votes on 0 Posts
Help with Flooring Suggestions

I am playing with some designs and wanted some suggestions what would be the best way to frame the ceiling of the garage and floor of the living space above.

I have attached my pdf of an idea of the layout of the ground level.

I do not want any support posts in the garage!

I was looking at using an engineered system from a company like this one.

http://www.wsitruss.com/pb_trs04.asp

My Layout

http://www.smartsystemsconsulting.co...es/layout1.pdf
 
  #2  
Old 03-11-04, 05:09 AM
L
Member
Join Date: Mar 2000
Location: Arlington, WA
Posts: 9,238
Received 0 Votes on 0 Posts
Depends on what your local building department will approve!!
 
  #3  
Old 03-11-04, 02:55 PM
R
Member
Thread Starter
Join Date: Jan 2003
Location: CT
Posts: 206
Received 0 Votes on 0 Posts
Thanks, I know ultimatley it comes down to the local AHJ, but what I am looking for is some advice.

Are my spans realistic? Can it be done with engineered wood beams? Will steel be required?

Also how would it be laid out? One Beam run horizontal down the middle and all other floor tursses from there or should the main beam run parallel to the front of the house?

I believe my local authority requires 40psf support, so those of you who can calculate span vs. beam sizings, how bout some help.

Thanks, and again this is more for me to visualize how it would lay out I am not going to build it myself!
 
  #4  
Old 03-13-04, 09:30 AM
trance's Avatar
Member
Join Date: Aug 2003
Location: usa
Posts: 406
Received 0 Votes on 0 Posts
Well, the trusses you're showing are engineered for at least 40 psf, at 2'-0" on center. And they span up to 28 feet.

Here's what you need to tell us now:

1) is this a new house or is it an existing house?

2) if it's an existing house, do you have enough room to fit in a truss that is 18 - 20" deep?

3) which direction do you want to span? You only give the dimension in one direction.

4) it looks like the walls of the garage are 29' apart. The trusses you are looking at only span 28'. I'm sure you can get a company to build a truss that spans 29' too.

Basically, if this is a new project, wood trusses are an excellent way to go. I use these all the time in long span residential projects, and they are also great because the offer space to run wires, pipes and ducts.

generally the floor is built from these trusses, and a 1 1/8" thick plywood t & g subfloor is put on it. It makes a very strong floor.
 
  #5  
Old 03-13-04, 10:15 AM
R
Member
Thread Starter
Join Date: Jan 2003
Location: CT
Posts: 206
Received 0 Votes on 0 Posts
1.) This is for a new house

3.) Theoverall dimensions are 36' wide for the house and 45' long.

I am planning on spanning the garage. Dunno which direction though.

It is 29-30' deep but 26-27' wide. Still working on what exact measurements but that is very close to what I am planning.

Since they manufacture 28' long trusses I guess I could have them span from left to right. Correct?

You said 2' on center, is that common for a flooring system? Seems kinda wide to me?
 
  #6  
Old 03-13-04, 10:30 AM
trance's Avatar
Member
Join Date: Aug 2003
Location: usa
Posts: 406
Received 0 Votes on 0 Posts
Yes, I prefer a closer spacing. However, the 1 1/8" thick plywood is very sturdy. You may want to ask the company you buy the trusses from about subflooring for the 2'-0" on center trusses. You could really save some money that way.

You definately want to span the "short" way, even if it's only a foot or two shorter.

(FYI - rule of thumb is that a joist (which is what these trusses are) will span the "short" way, while a beam will span the "long" way.)

Your local building dept shouldn't have any problem with you using trusses. They are pretty common. There may be firestopping issues you have to deal with though. (you may have to close off some of the trusses so fire can't spread throughout the floor structure).

Another rule of thumb - 24' is a minimum width for a 2 car garage. of course, the wider the better for all our american gadgets and clutter

good luck and let us know how it turns out.
 
  #7  
Old 03-17-04, 07:23 AM
glimbaugh
Visiting Guest
Posts: n/a
here are a couple of things

to consider.
First consider how your roof is going to be framed. If the interior walls showing on that plan are used for load bearing then the spans indicated in the provided link aren't accurate because they don't consider any additional roof loads.
Second if the roof isn't bearing and you are thinking about flor trusses then ask the supplier of those how much deflection (sag) might you expect. Then decide if that is an athestically acceptable figure. For example a floor span of 28' is allowed to have a total load deflection of l/240 as long as live load doesn't exceed l/360 and the answer is......1.4 inches is allowable by code.
 
  #8  
Old 03-17-04, 09:07 AM
R
Member
Thread Starter
Join Date: Jan 2003
Location: CT
Posts: 206
Received 0 Votes on 0 Posts
OK, if the roof is framed with trusses don't they usually put the load on the outside walls?

The roof plan will be simple nothing fancy.
 
  #9  
Old 03-17-04, 09:27 AM
trance's Avatar
Member
Join Date: Aug 2003
Location: usa
Posts: 406
Received 0 Votes on 0 Posts
I think what glimbaugh is saying is:

1) if the trusses bear on the interior walls the interior walls will be loadbearing.

2) if any roof load comes down in a spot that's not directly above a bearing wall (either interior or exterior) that roof load can cause the trusses to deflect & so the trusses would need to be strengthened to take that additional load

3) the design deflection of the trusses may result in more deflection than you'd like in your house. however, the code deflection is sized such that you probably wouldn't notice it.

At the end of the day, the trusses will have to be designed to handle the loads on them. The truss company knows this. The building department will want some proof (ie: drawings reviewed by an engineer or architect for the structural portions of the house, ie: trusses, etc) that the structual members are properly sized.

Truss companies commonly deal with the following issues:

1) extra loads coming down in weird places

2) large ducts coming through the trusses

3) cantilevers

4) etc...

I'm sure your basic design is fine. It is good to consider the issues that glimbaugh raised when picking the exact truss however.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: