Home Building Questions Forum
Forum
Here is your forum to share questions on any of the listed general topics. Remember as with any forum you can create new threads if you don’t see a topic that quite fits your question.
To ask a question please select a topic close to your question and then select new topic. This will post your question for multiple answer options. Please do not post questions in the comment section below or we will soon be overrun with comments…Thanks
Share Project Ideas
I am also encouraging ideas like sharing project designs you are considering while asking other registered members to give constructive input to help improve the design.
Building Professionals in Forum
If you are a Professional in the Home Construction Industry we welcome your contributions in our forum. You are welcome to add promotional information about yourself in your profile section. Our forum also includes a Private Message section to share direct contacts with other members!
Share Project Photos
Lastly this forum will will be a great place to post your favorite room or project pictures to share for design inspiration.
Welcome GuestShow/Hide Header |
|---|
Welcome Guest, posting in this forum requires registration. |
|
|
| Forum FAQ | |||
|---|---|---|---|
 |
FAQ Frequently Asked Questions Moderators: | Topics: 4 Posts: 4 | Last post by Jim Patrick in How to Insert an href Link in Your Post on February 26, 2012, 09:42 |
 New posts  No new posts |
Version: 1.0.34 ; Page loaded in: 0.387 seconds.
Monday, March 19th 2012 at 6:48 pm |
I need to replace the roof on a stand-alone screen house located in northern MN. The pitch on the roof is less than 1-12. Would you recommend that I use treated or untreated plywood for this purpose.
Thanks
Monday, March 19th 2012 at 7:13 pm |
The key here is to understand that both treated and untreated plywood are only as good as the glue used. Treated plywood will not rot but the plys will still delaminate if constantly exposed to moisture.
So if your plan is to install this relatively flat roof without some form of rolled roofing or rubber membrane protecting then my advice is to seal all surfaces and edges of the plywood with a good oil based paint prior to installation to seal out the moisture as well as possible.
Even with a protective roofing cover it is still a good idea to seal your exposed plywood surfaces to keep them from absorbing moisture.
Friday, May 18th 2012 at 10:55 am |
I am in the permitting process for a small 20’ by 24’ cabin in Northern Arizona. The building has a 12’x20 loft over the back half. The building is being carried on 4 – 12”x12” piers along each side and 4 down the middle, each resting on 2’ square footing. The question has to do with the bottom outboard rim-joists carrying the back half of the bottom floor, loft area and roof.
The span between the piers is 6’8”. The rim-joists in that area will be carrying 40 lbs live load each per floor and roof and 15lbs dead load each per floor and roof for a total load of 165 lbs per square foot. The rim-joists will be carrying half the load from the outside of the outer piers to the center = 5’ x 165 lbs = or 825 lbs per running foot evenly distributed over the span of the rim joist or 6′ 8″.
The building is scheduled to have either 7/16th or 1/2 inch OSB sheathing installed either across or parallel to the 2×4 @ 16” oc framing. The sheathing will start at the bottom of the outer rim-joist which I calculated to be doubled 2×8 Doug-fir.
If the sheathing is installed horizontally, the break between the panels on the first course would occur over the centerline of the footings, and the sheathing and framing system in my opinion would serve as a box beam or truss. I am willing to install blocking as a top cord at the top of the break between the sheets at 4’ or 8’ depending on the installation, and am willing to nail the sheathing on at some nailing schedule designed to accommodate the load. The top is in compression and the bottom is in tension.
This building is small and will only be used seasonally but the Coconino County Permitting Authority will allow no compensation for the sheathing and originally specified 5 1/8 x 10 glu-lam but now is down to a 3 1/8 x 9” Glue-lam or 4 – 2x12s bolted together to span the 6’8”.
Can someone provide me with the mathematics to demonstrate the load carrying capacity of the wall system including the sheathing?
Thanks,
Bill Cowan
Rimrock, Arizona
Friday, May 18th 2012 at 1:48 pm |
Hello Bill,
Thank you for visiting my site and for the interesting question. First I must clarify that I am not an engineer but I am a designer with over thirty years in this industry.
I am including a scanned image of the header table I would use to size your project and as you will see the design call-out for you situation would be a minimum of 3-2×10’s base on Hem-Fir lumber and a 40# roof live load.
I don’t know that you will have any success finding anyone to define a system rating including the sheeting and even if they did make a recommendation it still comes back to your permitting department’s discretion. Keeping in mind that the person we are talking about is just another person like you and I doing the job they were hired to do and technically they are liable for accepting or disapproval of any deviation from their approved standards.
So I would recommend that you consider taking this chart and visiting with them remembering that you will have much better success bringing a spirit of cooperation with the contact at the county permitting authority.
I hope this information is helpful and thanks again for checking out my site. This site is relatively new and so if you happen to be a Facebook user I would appreciate your liking our site as this seems to be a good way to get the word out that the site is here to help.
Sincerely
Jim Patrick
Home Building Questions