Sistering joists to level out a floor for a new bathroom. My prefrence is to use my framing nailer but I wanted to make sure I’m not missing the boat by using screws instead.
Thanks!,
JNF
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
From plumbing failures to environmental near disasters, OHJ staffers dish on our worst and best moments.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
Nails (and some construction adhesive).
You are looking for shear strength not the clamping action of the screw.
"Poor is not the person who has too little, but the person who craves more."...Seneca
I went through this a bit ago, and after reading far too much on the subject came to the conclusion to use Deck Mate 3" screws and PL Premium adhesive. The Deck Mates (http://www.deckmatescrews.com) worked MUCH better than the GripRites. There's a bit of a different head design, and I found that you could zip them in with the impact driver very easily.
For more info, see McDesign's response here: http://forums.taunton.com/tp-breaktime/messages?msg=84041.28
and Piffin's here:
http://forums.taunton.com/tp-breaktime/messages?msg=84041.64
If you want to nail, use hand nails as they'll hold the joists together tighter than the gun nails, and won't shake things up too much if you are concerned about that.
Not to disagree with the two quoted posters but I didn't see any mention of a plaster ceiling in this thread.
If I had I also would have recommended screws as least disturbing to the ceiling."Poor is not the person who has too little, but the person who craves more."...Seneca
Gun 'em at opposing angles... won't pull free that way and the next guy a hundred years from now with thank you for NOT glueing.
Troy - always thinking about the next poor schmuck.
Troy Sprout
"A free people ought not only to be armed and disciplined, but they should also have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government."
-- George Washington
Structurlly that will do the job - but why subject the poor HO to a hunderd years of enduring the squeaks?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I've never heard squeaks happen when the nails are horizontal in sisters, only vertical in the subfloors and underlayment... especially when they just miss the joist.
'course, I ain't been around a hundred years Troy Sprout
"A free people ought not only to be armed and disciplined, but they should also have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government." -- George Washington
it isn't that common. Maybe one in twenty or thirty times, but it can happen. So I insure against it.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I use nails and drive them in at an angle. I use different angles for the nails, so the boards can't possibly pull apart. It doesn't take much of an angle, either, but I use about 20 degrees.
For sistering you use a habit.
Use adhesive and either nails or structural screws.
Least chance of squeaks with screws and the glue
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Ideally, the sisters are fully supported at both ends so there's no structural need for fastening. When this isn't the case through bolting is probably advised, at least at the wild ends.
Once the piece is supported you're primarily helping to keep it from "walking" out of place and keep it from squeeking.
my two bits..
use the framing nailer. nail it properly. 2 rows 16oc angled opposite ways ( as others have described) you could go 12 oc if you want.
I've nenver found a squeak to originate from a horizontal application. when you walk on a floor that squeaks it is the nails in vertical plains that are the ones that sqeak.
I'm not against using glue or even really screws. but there's now good reason nailing wont work. otherwise I would trading my framing guns in for glue guns and drivers.
We often use screws to at least suck the new and old together when sistering to material that is less than straight, as is common with old twisted joists or rafters that have had the benefit of growing old without blocking or a reasonable span. Then it's finished off with nails.
Having said that my prefference is the structurally rated Timberlock screws. Being a smaller diameter than the harder to use 1/4" simpson screws, they start and drive easier with little splitting. Sometimes it's also easier to get into tight places with the screws and a 12" extension.
In a small area like a bathroom the extra cost of screws isn't bad.
Good sistering
Beer was created so carpenters wouldn't rule the world.