For the Advantech flooring users out there, what is you preferred method of fastening it to the joists/subfloor? And are you doing new construction or renovation?
With CDX, I usually screw it with no adhesive (in the back of my mind is the thought “what if I have to pull this back up”).
Huber site mentions nailing and gluing PL Premium Polyurethane Construction Adhesive and Titebond Premium Polyurethane Construction Adhesive.
jt8
“Real difficulties can be overcome; it is only the imaginary ones that are unconquerable. ” –Theodore N. Vail
Replies
I put my subfloor down w/ PL & 10d nails.
One thing I didn't get is that it requires MORE screws than nails. I wouldn't have expected that. My guess as to why is that screws must have less sheer strength than nails. Is that correct?
It really depends on the screw. There are a lot of screws out there made from junk steel, with barely any oversite as to quality - buy a box of Grip Rite and see how crappy they are. Then there are the ones put together by companies that also supply the Aerospace industry - buy a box of Phillips Deckmate to compare to the former. Neither of these is a code approved decking fastener.
Senco is one company that does make a code approved screw. They have the capacity to rigidly oversee their industrial manufacturing process so their screws always perform uniformly. There may be more, but I haven't seen them yet. Unfortunately all the suppliers around me that I've found are supplied by Grip Rite.
The fastening schedule for Senco screws is identical to 8d nails for sheathing - I don't remember about decking specifically (though roof decking is also identical to 8d). I think Advantec may require more screw fasteners due to the variability of the quality of fasters out there. Generally (according to Simpson and USP) wood screws are ASSUMED to be about 80% of the strength of nails... so I'm guessing Advantec is looking for 25% more screws than nails?
Screws and nails are very different critters, and behave in very different ways when force is applied. I think that screws provide a lot of benefits over the nail - in fact I did a number of amature engineer tests comparing them a few months back with some interesting results (do a search to find them). While nails may have supperior shear strength, they will never approach this value because they will pull out. Screws might have less shear stregth, but because they don't give way they provide their full potential before they fail.
Screws are really in their infancy (well, maybe they are toddlers now) as a construction fastener. Nails are currently the tried and true fastener. For screws to get where nails are today, they have to be able to be driven in as fast as a framing nailer, driven to the exact depth required ever time, be of uniform high quality, and be Code Approved by the manufacturers in nearly every construction use. None of this is about to happen any day soon.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Screws and nails are very different critters, and behave in very different ways when force is applied. I think that screws provide a lot of benefits over the nail - in fact I did a number of amature engineer tests comparing them a few months back with some interesting results (do a search to find them). While nails may have supperior shear strength, they will never approach this value because they will pull out. Screws might have less shear stregth, but because they don't give way they provide their full potential before they fail.
But for subfloor, does shear really play into it? I realize I'm probably waaay in the minority by screwing down my subfloors, but KaChunking my way across the floor with a nailgun just doesn't seem to have the same precision.
Oh well, maybe I should look at it as an excuse to buy a new compressor.
jt8
"Real difficulties can be overcome; it is only the imaginary ones that are unconquerable. " --Theodore N. Vail
John, you keep mentioning "precision" when comparing nails to screws. What's up with that? This is one case where I'll agree with the statement I usually cringe at..... "It ain't a piano". Just because you're using a nail gun doesn't mean you have to fire nails at warp speed. It ain't hard to hit a joist with a nail gun.
You also mention that you like screws because you can remove the subfloor. I agree. But sooner or later you're done taking that subfloor back up, right? Sooner or later it's time to glue it up, fasten it down, and move on. If you do ever have to pull the subfloor back up down the road, your biggest problem is gonna be the glue, not the nails... so why sweat it? It really is a waste of time, in my opinion. We get excellent squeek free installations using subfloor adhesive, proper nailing schedule, and paying close attention to hangers and other hardware. With the adhesives available today, hardware is my biggest headache when we're talking about squeeky floors.
We do gap sheathing where appropriate.... usually with an 8 penny nail.
Your weapon of choice for nailing subfloor?
jt8
"Real difficulties can be overcome; it is only the imaginary ones that are unconquerable. " --Theodore N. Vail
Hitachi coil nailer.
3 nails per second. Unhuh... That would push me to the dark side in a hurry ;)
PL, Titebond, something else, or it doesn't matter? (ie do you have a favorite adhesive for Advantech)
jt8
"Real difficulties can be overcome; it is only the imaginary ones that are unconquerable. " --Theodore N. Vail
I like PL Premium myself. But I've had good luck with DAP's subfloor adhesive as well as LumberLock. The only product I really try to stay away from is Liquid Nails but most of the yards don't stock it around here anyway, at least not as subfloor adhesive. I've never actually had a bad experience with Liquid Nails myself, but I've heard some stories, and that's enough to keep me away. A call back on a subfloor issue is not something I'm interested in dealing with. ;)
How is that addition coming along? You've got me thinking 2nd floor on my new project house, but I don't think the budget could swing it.
Can't remember seeing any pics from yours in a while.
jt8
"Real difficulties can be overcome; it is only the imaginary ones that are unconquerable. " --Theodore N. Vail
Yeah, I kinda wound down with the picture posting. It hasn't really changed much except that it's sided now. I figured y'all would get bored pretty quick with pictures of the plumbing, electrical, and HVAC rough-ins so I kept those to myself. It's getting insulated a week from Tuesday and B&P on Thursday. Oh yeah... and the painters are starting on the exterior on this Tuesday. That should make for some noteworthy pictures. I'll update after paint, how's that? Thanks for keeping tabs..... I'm glad someone's interested.
Those dramatic renovations are always neat to see as they progress. For God's sake, its not like you just changed the tile in the kitchen... you put a WHOLE new floor on the house! Maybe mundane for you, but the rest of us find it interesting. I'm sure you got people wondering how its going.
If anyone is replying to you after posting new pics, you gotta figure for every reply you probably have 10-15 people who are following the 'drama' without replying.
If the post drops like a rock after posting (without anyone replying), then you can figure its on the 'boring' meter. But that in itself is almost an accomplishment with this crowd (for them to find something construction related boring) :)
jt8
"Real difficulties can be overcome; it is only the imaginary ones that are unconquerable. " --Theodore N. Vail
Not that this $400 beast is in my budget, but how big of a compressor do you use with it?
View Imagejt8
"Real difficulties can be overcome; it is only the imaginary ones that are unconquerable. " --Theodore N. Vail
How fast do you want to nail? Its not just pressure but CFM delivered. Tank size increases your recovery time between shots. I usually tell people to buy the most they can afford or is practical for their job. Are you going to need portability? I think a good choice would be the Hitachi twin-tank at 2HP and 15 amps. That similar PC that runs on wheels is pretty cool also although I think it is oil-free which some people don't like. 2HP Emglo/Dewalt is good also.
Good luck, it is a great gun.
Terence
Shear would HAVE to come into play with floors. If you have a basement or crawlspace, you have lateral forces from hydrostatic pressure. Normally, it would want to bow the floor joist, but the subfloor would resist that. Similarly with a 2nd story, it would resist twisting from the wind.
They require more screws because screws have less resistance to shear than nails, because they have a smaller solid cross section of steel. And a subfloor is subjected to more shear forces, than uplift forces. The screws have better holding power, but they shear relativley easy, nails do not. As for the glue, it doesnt do any good to hold the floor down, but it does prevent squeky floors by holding the joists and the sheeting apart, and giving smooth mating surface. Thats why you dont wnat to let subfloor panels fall onto a bed of subfloor adhesive, it wll just squeeze out, you should lower it onto the joist. One customer of mine was doing job with 1 1/8" plytanium subloor and made a hook about 5 foot long so they could set them down without climbing out on the joists.
Edited 10/23/2005 12:08 pm ET by jrdiblumber
"As for the glue, it doesnt do any good to hold the floor down, but it does prevent squeky floors by holding the joists and the sheeting apart, and giving smooth mating surface."
I've not heard of this before. If glue is there only to provide a lubricated barrier and NOT a continuos wood to wood bond, then why bother with the glue which would seem to be the wrong substance for this application? Wouldn't a layer of polyethelene work better and be easier to apply - not to mention cheaper?
I know that using a dry lubricant is one method of eliminating squeeks on a renovation, but on new constuction?Rebuilding my home in Cypress, CA
Also a CRX fanatic!
It doesnt really act like a lubricant, more like a buffer. Even though the top of the joist mat be surfaced, it still isnt going to mate up with the bottom of the subfloor panels perfectly. Since the adhesive is soft,and liquid, it will mold itself to the contours of both pieces giving them a good solid match, kinda like weatherstrip in a door.
I dont know that something other than adhesive woudlnt wor, but their are a couple of points of concern with anything else. Firstly anyother products would have to be flowable, but still stiff like the adhesive, second, is the price, polyethylene is like 4.00 a 10.5oz tube last time I checked, liguid nails, or whatever adhesive you use, is anywhere from .99 to 1.99 on the top end, and 1.09 or so seems to be the average. Also I dont know that their would be any advantages to using a different product.
Edited 10/23/2005 3:41 pm ET by jrdiblumber
JR,You wrote: "As for the glue, it doesnt do any good to hold the floor down, but it does prevent squeky floors by holding the joists and the sheeting apart, and giving smooth mating surface."I cannot agree with that statement. I have demo's many glued floors, and one done correctly with good adhesive is a MAJOR PITA to remove without destroying what stays behind. In fact, the APA allows fewer nails for glue-nailed subfloors, and tests show that the completed assembly is stiffer than an unglued floor because of the composite action.Bill
Im sorry, Bill your right, I should have worded that differewnt. It does help old the panel in place. I guess I was trying to explan the whole mating thing, and misstate to emphasize my point. Sorry.
John, we use pneumatic ring shank 8's and subfloor adhesive. Mostly new construction. But during reno work we do the same. If other subs will need access to a floor with a closed ceiling below, we just tack the corners of the sheets in that area and skip the adhesive. We then mark the perimeter of the unfastened area in orange spray paint so they are not overlooked before finish flooring goes down.
Brian,
Would you come down here and frame stuff for me to roof? How come all tradesmen are not concerned with their brothers in arms on the same project, like you are? Keep going, man. Maybe it's contagious.Birth, school, work, death.....................
I just caught your post to me. To answer: Sure, I'd love to! Find a GC to pay the travel and room/board expenses and I'm there. ;)
I try to do my part. I like to think, what comes around, goes around. If nothing else, I get thanked for it occasionally and that's usually plenty. It's not like it's a tough thing to do or anything..... skip a few nails and some glue. Come to think of it... it probably saves me work.
Oh.... and it's not contagious. I once had a plumber tell a homeowner that it's a good thing he pulled up the subfloor as the framer didn't even glue or nail it down. Yeah.... where would I be without those plumbers. ;)
I probably should just embrace the nailgun and leave the screwdriver on the shelf, but it's hard for me. A piloted screw is just so much more precise. Can be placed and/or removed without causing much grief to the material.
The nailgun is a lot faster, but just try getting that sucker back out cleanly. I've done ringshanks w/o the adhesive and didn't like the results. Floor creaked in places and you couldn't get those dang rings out without tearing stuff up.
Just... gotta... become... a...nail...person... Feel like I'm heading towards the dark side.
How much time you got when you drop that Advantech down on the adhesive before it decides you ain't gonna get to move it any more? Are you leaving about 1/8" wiggle room on the sheets, or jamming them in tight?
jt8
"Real difficulties can be overcome; it is only the imaginary ones that are unconquerable. " --Theodore N. Vail
Edited 10/23/2005 12:22 am by JohnT8
we use pneumatic ring shank 8's and subfloor adhesive
2.5"?
jt8
"The ultimate result of shielding men from the effects of folly, is to fill the world with fools." -- Herbert Spencer
2 3/8" actually.View Image
we use any standard const. adhesive in the quart tubes ( we have an air powered caulking gun )
and we use 8d ring shank nails in our coil nailer...
screws ? ... we don't use no stinkin screws...
One of these days, I need to take about two weeks off and camp out with a regular construction crew. I have a tendency to expend too much time and effort trying to get it perfect rather than getting it done. I think the lack of efficiency in 'getting it done' is one of the big differences between 'pros' and non-pros.
Some time with a regular crew ought to learn some good habits. Learn when its time to spend extra effort and when you should just nail it off and move on.jt8
"Real difficulties can be overcome; it is only the imaginary ones that are unconquerable. " --Theodore N. Vail
Why not use screws? The PL keeps the advantec down and screws have better withdrawl resistance. We use quik-drive screws and one guy can keep up with a couple of guys laying it down ahead of him. When everything shrinks, the nails are more likely to allow movement on their shafts (squeaks) We also glue the heck out of the hangers when using TJI's, we have had squeaks there before we started gluing the hangers.
I know you addressed your post to Mike Smith, but I'd like to answer if you don't mind. If you do mind... just ignore me... I'll go away sooner or later. ;)
I don't understand why some folks want to re-invent the wheel. I'm sure you are right that screws have better withdrawal resistance compared to nails. But have you ever tried to pull a ring shank nail out of a laminated I-joist? Nine times out of ten the head comes off the nail before you can get it out.
Even with conventional lumber, ring shank nails do a fine job. I don't believe I've encountered a squeek issue with a properly nailed subfloor that has been installed with subfloor adhesive. The squeeks I see now are always related to top-flange I-joist hangers or 'shiners' (nails that just missed the joist and squeek against the side of the joist) Your screws would have the advantage with shiners as it's easier to tell when you've missed with a screw than it is with a nail gun. But if you've used a nail gun much, it quickly becomes obvious when you missed.
I make my guys go back and knock out shiners in all sheathing and replace them with a hand nail. I think shiners make a job look like someone was flying and not giving a crap. Frankly, they embarass me. So knocking them back out kills two birds with one stone. It makes the job look better and it makes the guys pay more attention to what they're doing.... resulting in less shiners. Not much fun climbing up a gable wall to fish a shiner out from behind the tyvek.
Anyway... I just think that screwing down subfloors is just too labor intensive and slow for today's framing market. Especially when, IMO, nailing it off does a fine job and meets industry standards of a properly performing floor system.
we always do shiner patrol.. it makes the newbies more aware of what they're doing right .... or wrong
screwing has never impressed me as a superior method of applying any kind of sheet goods.. if you follow the nailing schedule you will get just what you need..
before , when we were using 3/4 fir T&G , P& TS, we'd get warped sheets... nothing would pull them down.. screws, double nailing.. it would all just bury instead of pulling down
and then later when everything dried out , some of the warp would disappear and you would get squeaks.. but it didn't make any difference wether it was nailed or screwed
now , with Advantech, we get good flat sheet goods , and 100% contact with our construction adhesive...
as for hangers... i haven't seen any squeaks ... our hanger nail nose encourages filling every hole
ain't it great to be perfect ?Mike Smith Rhode Island : Design / Build / Repair / Restore