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Housing - New Build: OSB SCREWS

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  1.  
    • CommentAuthorflexon
    • CommentTimeNov 18th 2016
     
    Can anyone please advise on the best screw type to fix battens to sips pannel osb. board
    • CommentAuthorringi
    • CommentTimeNov 18th 2016
     
    Screwfix TurboGold or Turbo II will go into OSB without have to pre-drill holes etc. I now use their Turbo II screws as I like the TX head.
    • CommentAuthorDarylP
    • CommentTimeNov 18th 2016
     
    TX head every time! The chisel point cuts its way through the OSB outer layer.
    • CommentAuthorcjard
    • CommentTimeNov 18th 2016 edited
     
    I personally wouldn't use a self drilling screw on OSB; it doesn't have a great pullout resistance to start with, and to then use screws that a) actively drill material away rather than push it aside and b) have a relatively shallow thread depth means that you don't really get the clamping force youre after unless you can find one that is unthreaded to the same extent that your batten is thick

    Instead I'd advocate using plain old plasterboard black phosphated coarse threaded screws, predrill the batten to the same size hole (or half a mil smaller) than the thread is wide so the screw thread doesn't grip the batten, and put a dot of pva at each screwhole. PB screws have an incredibly sharp point and start in OSB easily. You can always thump the back of your cordless with your free handonce you've got it lined up if you feel the need to help it start

    The screw will clamp well, flattening that pva out to a wide contact patch. It'll dry giving you a far stronger bond than mechanical fix alone. It needn't take significantly longer than any other method involving less prep, especially if you can recruit a helper to pre-drill, assign screw and dot glue the next batten while you're fixing the current (or if you predrill and assign screw to a pack of battens, then just apply the glue as you take each one)
    • CommentAuthorcjard
    • CommentTimeNov 18th 2016
     
    Also worth mentioning:

    drill your holes/fire in your screws at alternating slight angles perpendicular to the run of the batten. This way rather than having a line of screws that are 90 degrees to the wall you'll have e.g. an 80, then a 100, then an 80... it'll mean the batten rocks far less should there happen to be a screw or two that doesn't pull quite flat

    For out an out speed, use a nail gun loaded with 50mm galv ring nails, again fired in alternating angles just off 90 degrees
    •  
      CommentAuthorfostertom
    • CommentTimeNov 23rd 2016 edited
     
    Posted By: cjardFor out an out speed, use a nail gun loaded with 50mm galv ring nails, again fired in alternating angles just off 90 degrees
    If that's a gd option, it sounds dramatically quicker than any screwing let alone pre-drilling and glueing! So what's the downside?

    It's like what builder insisted, on last job, instead of screwing OSB bubble-glued to studding. I allowed it, with caution about whether the boards really get pulled in tight. Maybe nail-gunning is actually going to pull tighter than screwing?
    • CommentAuthorMarkyP
    • CommentTimeNov 23rd 2016 edited
     
    my 11mm OSB sarking has been nail fixed with 51mm galv ring shank nails and it seems to hold very firmly. No glue or silicone used during the fixing. The sarking is both a structural and air tightness layer. Good luck getting contractors to pay attention to alternating the nail gun angle, but you'll probably get that by accident rather than design in any case. I asked for nails every 200 - 250mm, else would have been lucky to get them at 400s. You do need to watch nail head penetration depth, set too deep it can drive the nail most of the way through a sheet of OSB (and more so I would think with 9mm OSB). I had to keep an eye on this aspect, though I also have counterbattens nailed through the OSB into rafters with 75mm ring shanks which further fix and clamp the OSB.

    (how air tight without glue or silicone? I used tecson tape over all the joints. Will the tape last? I had some doubts but the vertical joints are then counter battened, which further compresses the tape seal. As a failsafe, I will also silicone down each side of the rafter along the OSB/rafter joint and also silicone thin lathes over each horizontal joint from below. In hindsight, wouldn't have bothered with the tape.)

    *edited for clarity
    • CommentAuthorbarney
    • CommentTimeNov 23rd 2016
     
    If memory serves correctly, the nail centres for OSB3 (assuming at least a 3mm ring nail at length of at least 2.5 times the board thickness, is 300mm for vertical wall sarking and a surprising 100mm for roof sarking. Nails should be approx. 8mm from edges and the minimum bearing area for board edges is circa 18-20mm.

    My tame structural engineer is very particular about getting that achieved on site

    There is always a bit of angular variation in the gunned nails as the operative guns in everything he can reach from one position before moving on

    Most of the guys I've seen have all sorts of bits of tape on the nail slide or the gun itself to give them approx. gauge marks for nailing distances

    Regards

    Barney
    • CommentAuthorringi
    • CommentTimeNov 23rd 2016
     
    Gunned nails have glue on them that melt as the nail goes in, if you have every tried to remove one you would not question how well the hold.

    However they don't pull the board to the studs, it depends on hole tight the board is hold while being nailed, therefore I think the expanding glue or tape is still needed.
    • CommentAuthorMarkyP
    • CommentTimeNov 23rd 2016
     
    whether this a valid reason or not, I dont know but we considered glue as both a means of additional fix and air tightness but decided against it becuase of the expansion gap between each sheet. If you intentionally fill the gap with glue for air tightness, or inadvetently fill it becuase the glue bubbles into the gap after a dollop of a bead is applied to the rafter, wouldn't you effectively reduce the working size of the expansion gap? Bubble glue I've used on my egger floor seems to take on a compressible foam like state when expanding into a void which could be helpful, but nevertheless I thought that the full 3 - 4mm expansion gap we left would have been reduced in effective size if filled with glue. I couldnt see that over sizing the gap to compensate would help as you then have issues with the gap reducing the already meagre bearing of your OSB edges on your skinny 45mm of rafter. for this reason decided it would be as well to seal with tape and then belt and braces with silicone along the rafter/OSB join and the horizontals with wide lathes, preserving the expansion gap.
    •  
      CommentAuthorjoe90
    • CommentTimeNov 23rd 2016
     
    I wouldn't say nail gunning would pull tighter than screwing but I have found it just as tight ( as long as you don't want to take it apart after:angry: it's so much faster, not sure if it's cheaper either. I plan to fix osb inside warm roof and glue and "fix" all joints and to save wastage these will not be on rafters but between with strips of OSB glued and "fixed". I like the idea that a building can breath so I won't be using tapes and membranes.
    • CommentAuthorMarkyP
    • CommentTimeNov 23rd 2016
     
    Is your OSB over rafter? deck for your warm roof insulation? Assume the OSB isn't structural as otherwise puzzled how you side stepped what seems to be the accepted standard of short edges fully supported on a rafter.
    •  
      CommentAuthorjoe90
    • CommentTimeNov 23rd 2016 edited
     
    Sorry didn't explain properly. 400mm I joists as rafters, osb inside with joints glued and fixed (non structural but can't do any harm), 400 mm rockwall batts insulation, breathable membrane, counter battens, battens, slates. Is what I propose and building control have passed, I may paint the OSB to make it more " air tight" but as I said before I like the idea of " breathable".
    •  
      CommentAuthorfostertom
    • CommentTimeNov 23rd 2016
     
    What's your special meaning of 'fix' Joe?
    •  
      CommentAuthorjoe90
    • CommentTimeNov 23rd 2016
     
    Either screws or ring nails, :bigsmile: if I join the osb with another small piece of OSB I would probably screw as nails are better into " real" wood.
    • CommentAuthorcjard
    • CommentTimeNov 24th 2016 edited
     
    Posted By: fostertom
    Posted By: cjardFor out an out speed, use a nail gun loaded with 50mm galv ring nails, again fired in alternating angles just off 90 degrees
    If that's a gd option, it sounds dramatically quicker than any screwing let alone pre-drilling and glueing! So what's the downside?

    It's like what builder insisted, on last job, instead of screwing OSB bubble-glued to studding. I allowed it, with caution about whether the boards really get pulled in tight. Maybe nail-gunning is actually going to pull tighter than screwing?


    Downside? Material and tool cost I suppose. Wouldn't want to lay out 300 quid on a gun and 60 quid on a box of nails just to tack a few battens on. If I had a thousand to do on a roof, different story, might not get a gas gun again though.. Too much maintenance.

    The guns the boys use to whack timber frame panels together are different, use compressed air. Those you can just hold he trigger and touch the nose on the work to fire a nail. Very fast; got a video somewhere of Slinky Chris and Deepthroat Dave (don't ask) putting my timber frame panels together.. 7 minutes a panel I think..

    Important to note, regular gas or cordless guns use nails that have a clipped head, because they all lie together in a diagonal arrangement bound by paper tape. These nails aren't rated for nailing structural panels together. The compair guns take proper full round headed nails on a coil of wire, and these are

    As to whether they pull tighter, to some extent it depends how hard the workpieces are pressed together beforehand. Sheet materials like osb will be pulled tighter but studs may not. If the osb is far from the stud it is being nailed to then the sink depth setting on the gun will determine whether the gap closes up. Sink depth shouldn't be too high as the gun will successfully drive the nail all the way through the sheet. Consequently if there was a gap of 10mm between an osb sheet and the stud, the sink depth set to 1mm and he osb strong enough to resist that 10mm gap closi up when the gun is touched on it, then you'll probably end up with a 9mm ish gap after the nail is fired. At that point you reach for your old school hammer.,
    • CommentAuthorcjard
    • CommentTimeNov 24th 2016
     
    Posted By: joe90Either screws or ring nails,http:///newforum/extensions/Vanillacons/smilies/standard/bigsmile.gif" alt=":bigsmile:" title=":bigsmile:" >if I join the osb with another small piece of OSB I would probably screw as nails are better into " real" wood.


    Don't neglect the factor that for thin sheets you'll only be using short screws and it would be unusual to find short screws that have a partially threaded shank. The unthreaded part necessary for the tightest pull of the top sheet against the bottom sheet is unlikely to exist in the dimensions required for the sheets you're fixing (e.g. A 20mm screw, 9mm of which is unthreaded, for your two 9mm osb sheets). As such you'll probably be using fully threaded screws and getting a tight fix will either involve drilling the top sheet, or leaning on the screw and driving it until the thread has chewed the top sheet up inside the hole, but not chewed the bottom sheet up. This point would be hard to achieve without chewing the bottom sheet too and reducing the pullout resistance of the fastener.

    Overall I think nails would give a superior hold, especially when one takes the speed of fixing into account
    • CommentAuthorEd Davies
    • CommentTimeNov 24th 2016
     
    Posted By: cjardImportant to note, regular gas or cordless guns use nails that have a clipped head, because they all lie together in a diagonal arrangement bound by paper tape. These nails aren't rated for nailing structural panels together. The compair guns take proper full round headed nails on a coil of wire, and these are
    Is that the difference between first-fix and second-fix nailers?
    • CommentAuthorcjard
    • CommentTimeNov 25th 2016 edited
     
    First fix nailers are big brutes, can pound a 90mm nail 10mm into solid studwork. The nails are held together by paper or plastic tape, or wire. Nails are usually bound together at an angle if one side of the head is clipped off or they're arranged separated with full size heads

    Second fix nailers fire pins about a mm square and up to 65mm long. They're held together by some plastic film, like staples are. They exist in straight or angled variants. The guns are smaller, lighter and not as noisy. The idea of the small pin is you can pound it just below the face of e.g. The skirting and it will be relatively invisible.. Or easy to fill
  20.  
    Sadly, the DeWalt 2nd fix nailer I borrowed could even get close to putting a nail through my strand woven bamboo skirting - they certainly aren't heavy duty in any way - softwood only.
    • CommentAuthorcjard
    • CommentTimeNov 26th 2016
     
    Oh I don't know.. while fitting my underfloor heating spreader plates I tried stapling them with a hammer tacker to the eggerdeck (chipboard but with some sort of super hard waterproof coating) and failed. Ditto the compressor powered air stapler; that just wrinkled the staples.. fortunately I'd purchased a Hitachi first and second fix nailer pair and found the little nailer pounded brads through the sheet and flooring all day long..

    Did you try rubbing the end of the brads with a flap wheel in the grinder to sharpen them a bit?

    I'll let you know how I get on with brad nailing the beech skirting.. should be interesting!

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