# Nails or Screws for Joist Sistering?



## 1victorianfarmhouse

I have some joists in the basement that were cut for clearance and then additional wood was nailed on to "strengthen" them.  Some of the pieces nailed on are not very tight due to little room or poor angle to swing a hammer.  

If I were to redo these with properly cut wood that fits, should I use certain nails or screws for shear strength?  I am inclined to use screws as it's easier to access them to tighten properly.

What sayeth the experts?

Thanks,

vince


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## nealtw

Code calls for three nails every 16" and screws don't come close to nails for shear strength. If your new pieces are full length, sitting on walls on each end, you wouldn't have much shear load on the screws.
The trick to getting them tight is to use a clamp to hold them tight together to start with. The smooth part of the screw has to be more than 1 1/2" to pull a gap closed and a nail or screw on a bit of an angle will hold a gap open.


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## inspectorD

I agree, and those tight areas are no longer an issue. I own 2 of these, http://www.toolcenter.com/8400.html

Makes for easy nailing in tight quarters...and joist hanger nailing..ect.


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## Wuzzat?

Using the engineering toolbox website you may be able to calc. the shearing force between joists used for sistering and so decide if you need nails, screws, through bolts or duct tape.
Right now my higher cognitive functions have been disabled by a high BAC but tomorrow I may be of more help here.


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## nealtw

If you have air for a nail gun. A framing gun will fit into a 10 1/2" space.
Inspector: We used those nailers for hangers until we got a Strapshot gun from Bostich.


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## inspectorD

nealtw said:


> If you have air for a nail gun. A framing gun will fit into a 10 1/2" space.
> Inspector: We used those nailers for hangers until we got a Strapshot gun from Bostich.



The Joist nailer guns make it so easy!! 
Yes you will need a compressor...but if your here for diy,,,get the tools you will always use. a compressor is a big component to DIY.
Christmas is comming, and there is always someone sellin a used one!

My palm nailer came with all kinds of fancy stuff ,in a kit. Roofing, finish and spike nail attachments,a scraper, and a rubber mallet attachment. along with all the seals for rebuilding when it see's some age.
I even used it to bang out some copper for a distressed look a "designer" came up with!


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## nealtw

I even used it to bang out some copper for a distressed look a "designer" came up with!
I like that idea. I,ve used it as a rivet gun.


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## 1victorianfarmhouse

Thanks, guys.  That's all great info coming from people far more experienced than I.  I do have a compressor, not fancy and from 1972, but works good for these kind of smaller jobs.

But Christmas IS coming.....anyone have any comments on the Harbor Freight Palm Nailers vs the more expensive ones sold elsewhere?

Like I need more tools....

Pictured is some of the previously done "handiwork" I get to deal with.  I can wiggle the one in the foreground with my hand.

vince


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## nealtw

That's ugle enough. Dos'nt look like you can get the new piece on the wall like you would want. Pipes and wire should be drilled thru the center of the joist. Is the blocking against the brick just a 2x4 or is it thicker?


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## notmrjohn

"Harbor Freight Palm Nailers"
HF's motto should be, " Where the customer is quality control."
I've never used their palm nailer, I have a  $20 brad and staple nailer that I have used and abused for for over 10 years, it gets plenty of use and I have never had a problem with it. I have a $60 multi-angle framing gun almost as old, no problems with it. The first Multi-function  oscillating tool I got from them just stopped working after a haqlf hour, the replacement has been cutting every thing from cast iron to vinyl tile for 5 years.

With their no question 90 day guarantee, 30 day period to buy extended warranty, sales and coupons , it can be worthwhile to risk the small amount of cash. Especially for a casual user.  If the store is not so far away to make the return trip a hassle. When you get the tool use the heck out of it, even to point of abuse, try to wear it out before the warranty wears out. If it lasts that long it will probably last. If within 30 days its still seems OK the extended warranty may be worthwhile, but with sales and coupons it may be cheaper to buy a new one. 
 Of course for a casual user of an unfamiliar tool, it may be difficult to determine if the tool is not working exactly right or if the user isn't using it exactly right. Usually a HF tool works fine or doesn't work at all. Usually a HF is as good or better than low end tools from HD or big boxes, at much lower price. Often they are same tool.

With a low end palm nailer from any where, you are liable to get as much pounding on your hand as on the nail. For a DIYer on a smaller job, that might be bearable. And you could rig up some extra hand padding.

As to shear strength of nails vs screws; Just go to a bigger size screw. A 16D nail gun and a #8 screw both have a shear strength of around 90 lb. http://www.builderonline.com/construction/dear-builders-engineer-nails-or-screws.aspx When sistering I use some screws to pull them together anyway.  I usually use some lag screws or bolts, a wrench won't bugger the head like a screw driver can, and you can get a wrench or ratchet into tighter space. 

HF sells angle drill  and angle adapter for drill, so you can drill pilot for lag screw or all the way for a bolt. ( BTW I am leary of HF battery tools, in low end tools its the batteries, it seems they don't hold as much charge and wear out faster.

That is some "handiwork" indeed, they've turned those 2X 12(?) into 2X6's. The piece you can wiggle is doing nothing but holding up the pipe. I dunno what the  background one is doing, mebbe holding itself and the light bulb up. That far pipe hole is awful close to the edge. You may have to chisel out some brick to get some end support for new joists. Or put some columns under ends. How much of a chore to disconnect pipes and bore the properly sized sisters properly?


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## 1victorianfarmhouse

Thanks Neal.  There is enough room, just barely.  The piece you see is a little bigger than a 2x4.  The piping will come out and be rerouted properly.  Same with electrical, but for giggles, the light fixture you see in the background is in the back of a shower.

NMJ,

Thanks, I too have several HF tools, and they've held up to plenty of abuse.

As for the screws, one of the other reasons I like them is because they create less shock compared to pounding on nails.  I've found some lag screws to break easily, there may be more quality issues with them than screws.

I've got the angle drill attachment, and have also used wrenches and sockets to tighten some screws where there wasn't much room.

When I get to this job, I will support the joist and take out the added parts, trim the joist to make the cut area as close to square as possible, then put in a carefully cut-to-size piece and sisters.  And fill the damn holes with parts cut from dowels.

Thanks,

vince


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## nealtw

You don't have much to attach to so anchoring a 2x? to the concrete wall under the ends wouldn't hurt, nice shower vent too?


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## notmrjohn

Screws " create less shock compared to pounding on nails."
I'm with ya there.  And when you, I mean when I screw up the installation with screws, its easier to take it apart and start over than when I screw it up with nails. Wait... I mean when I nail it down perfectly, I haven't screwed it up and then.... no, that ain't it either. When a lag screw breaks a nail, an emery  board....awww screw it!

You're just over tigtening the lag screws. At least with driver driven screws the head usually gets buggered B4 it over tightens, in fact that's one reason Phillips heads were invented. The driver is suppossed to cam out before over tightening  or breaking the head off.  Of course when the head is buggered or broken off its hard to dissasemble something that got screwed up, or down or.... ummm, I think this is where I came in and every one else left.


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## Wuzzat?

notmrjohn said:


> in fact that's one reason Phillips heads were invented. The driver is suppossed to cam out before over tightening  or breaking the head off.


Yes, for automotive use.  

Posidrives reduce this benefit/problem.


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## nealtw

The problem with phillips screws is it is hard to tell if it is really a phillips or reed and prince or the one from Japan. They all have a different angle.


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