bolt on ledger instead of nail

MarkAndDebbie · December 22, 2009, 09:27:14 PM

I have considered using two 3/8ths through bolts for each set of doubled 2x12s in the loft floor instead of just nailing them. I seem to remember someone doing this. I thought it might feel more firm. Any thoughts?

(Note this wasn't replacing the ledger - I've already cut that in)

harry51 · December 22, 2009, 10:12:03 PM

It's tough to comment without more information on exactly what this bolted member is (ledger, joist, beam, etc.), how long it is, what the estimated load is, and if the bolts hold two parts of the member itself together, or if they attach it to the building, and if so, what part of the building they will penetrate, etc.

December 23, 2009, 12:05:50 AM

Whitlock and I just took apart a beam nailed 2-1-2-1-2-1 all the way across - actually he did most of it and I assisted. It was a 25 footer made in around 1940 and still good today. No indication of any weakness or loosed nails there at all. The beam boards have already assumed a new life - who knows - maybe another 70 years or so.

I don't think you would see a difference between nails or bolts if done that way. My opinion would be that unless you put the same number of bolts as nails that the nails would be stiffer. Nailed properly, the nails will hold more than the beam will support. They just function in shear keeping the beams together so both carry the load equally. They more equalize the differences in the two boards than carry much load themselves. They will not allow the boards to work independently - same as the bolts so I think the feel would be the same.

That is assuming I am picturing it right.

Whitlock · December 23, 2009, 12:26:53 AM

It would look better if it is exposed.

glenn kangiser · December 23, 2009, 12:45:14 AM

Hmm - I think I pictured that wrong too..... I will wait for more info...

December 23, 2009, 08:17:51 AM

(John's 1.5 story 32x20 with half loft)

My original question was at the stud behind the wall - but yes I'd like to do it all the way across as well for visual appeal on the exposed "beams." I don't think the loads are a question here as the single 2x12 SYP will span, but connecting them (all 3) should decrease deflection. The shear forces would be the roof weight trying to spread the walls (BTW -12/12 roof) and the wind pushing the house sideways (not a high wind / earthquake area).

Bolts may also be easier to pull the boards together.

This is the loft joist connected to the stud and a 2x6 spacer. I'll use the gap as a wire chase. Here are some pictures to help - there are 3 bolts in purple, 2x12 are orange, stud is yellow, 2x6 spacer is blue, and ledger is green.

and from above

Pictures are worth a thousand words.

diyfrank · December 23, 2009, 09:09:35 AM

I see 2 purple bolts threw the wall stud and the 3rd to what?

Bolts look nicer.

harry51 · December 23, 2009, 09:58:07 AM

IMO, bolts, large flat washers on both sides, and nuts should be fine for the job as shown. To spread the load out over as much of the wood as possible and for appearance on the staggered row of bolts that show along the length of the joist, malleable washers might be a good option.

http://www.acehardwareoutlet.com/(wdpytqfsejhlis45xktgwo3r)/ProductDetails.aspx?SKU=5304712

MarkAndDebbie · December 23, 2009, 07:51:43 PM

Quote from: diyfrank on December 23, 2009, 09:09:35 AM
I see 2 purple bolts threw the wall stud and the 3rd to what?

The third is through a 2x12 then a 2x6 (the blue thing) then the other 2x12. I think bolting them together will stiffen them. I only showed one of these, but they would keep going the length of the 20'.

December 23, 2009, 11:33:41 PM

QuoteMy original question was at the stud behind the wall - but yes I'd like to do it all the way across as well for visual appeal on the exposed "beams." I don't think the loads are a question here as the single 2x12 SYP will span, but connecting them (all 3) should decrease deflection. The shear forces would be the roof weight trying to spread the walls (BTW -12/12 roof) and the wind pushing the house sideways (not a high wind / earthquake area).

The best design is going to arrest the rafter thrust before it gets to the kneewall IMO. Either with a structural ridge or ties in the lower third of roof height. At that point this is just holding the boards together. Adding lumber does make things stiffer, the bolt or nail shouldn't make any difference to stifness of the assembly as long as either is well connected. Many nails do a better job of distributing the stress throughout relatively weak wood rather than few bolts concentrating stresses which may not harm a bolt but are quite able to harm the wood. You don't have anything like that stress here if you took care of the roof so taste is all that matters. I've drawn uniform herringbone, angled nailing patterns on exposed built up beams and it looks workmanlike, its not high art but its honest. Just mentioning that for when you wander down and price bolts.