reinforcing existing floor 3

[calculor]

Working on a project where the existing TJI's are overstressed. I'm thinking about adding joists to reduce the tributary width problem is Ican't get any nails into the joist. I'm considering using an adhesive inlieu of the nails. Anybody know of a reference for construction adhesives that gives mechanical properties.

 

[dik]

I usually use Bulldog PL Premium by LePages... you might look into it... stikkier than a ...

Dik

 

[jike]

I have a good friend who builds circular wood stairs and uses Gorilla Glue for everything and swears by it. I don't know if properties are available.

 

[DaveVikingPE]

This is a pretty good website on glues:

http://www.thistothat.com/.

Lepages is mentioned.

 

[whyun]

A star for Dave for a cool link.

As for the original post, if there are new TJI's added between the existing, I would try to use a more positive attachment. One suggestion is to use a short Z-clip on each side of the TJI top flange with short screw up to the sheathing and nail to the TJI flange.

 

[calculor]

Whyun
My initial concern is how to quantify the amount of shear the adhesive can take resist. However with the Z clip idea I think I can get a better feel with type of connection.

 

[whyun]

calculor, based on the bond strength of adhesive you may be able to calculate the amount of allowable shear transfer; however, it may be difficult to get that through the building department. ICC may have some test reports (or may not) but even then the building department still has the authority to prohibit the use.

For the Z-clip, I'd use the length comparable to a Simpson A35 clip with two fasteners at each attach points, staggered each side of the TJI flange.

 

[dik]

yup... excellent site

Dik

 

[dik]

Gorilla glue is a polyurethane that 'foams' and can fill less than perfect joints... pretty good stuff.

Dik

 

[SlideRuleEra]

"Adhesives In Building Construction", free 165 page, .pdf from the USDA Forest Products Lab

http://www.fpl.fs.fed.us/documnts/usda/ah516.pdf

http://www.SlideRuleEra.net

 

[calculor]

Thanks guys for the information especially both of the reference sites. I think I'm going to use both clip angles as suggested by Whyun as well as PL400 construction adhesive just to be on the safe side.

 

[dik]

Again, thanks Dave... your link has prompted a manner of repair, see Thread507-181574

Dik