need suggestions for nailing method on t an g ceiling

hi again, its cypress 110 by 20 straight from the mill, and will be fitted to pine battens and the roof space is about 300 mm under a low pitched tin roof. the home owner intends to put a clear laquer on it....i was thinking a 50 mm t nail, one thru the edge of the chamfer and one in the guts of the board to help the boards stay flat...also do i need to seal the backs of the boards first so that once lacqured moisture escapes from the boards evenly ?...and then there is the issue of useing the correct specified nail, perhaps a ring shank should anything fail i dont want to be responsible for useing the wrong fixings...is there a website that states the correct fixing nails?...perhaps because of the difficulty of puttying the nail holes in the small chamferred section i should just nail 2 in the guts of the board. hope to hear some ideas from you, thanks ...russ

Russ,
You say it is straight from the mill, is it dry or or has it been machined green?

Is it to be the full house ceiling or one room? If it's a biggish job a nail gun would be the right approach and using fine guage nails. Not treating both sides is creating the chance of each board 'cupping' because of uneven moisture loss, and pulling the nails.
....... and an answer to Kev's question is needed for additional comment.

soth

it will be a special run and i have asked for it to be within the legal moisture content range but will try to acclimatise it on site b4 installation...i am just a bit suss on what to expect knowing it has not been stored for any period

Just last year we finished our entire ceiling with T&G type [just on 1600 metres] - the original plaster ceiling was not glued at all and was sagging between the screw fixings - we have an exposed step where they actually join [can't really recall the actual profile name] - the reason being that should they "gap" it would not be as visible.

As the trusses were 25 year old [very] hardwood - we had to nail through the faces - 7000+ nails - we also used a "sausage" type of fixing glue to run along at each fixing point.

The finish was dimension 4

It looks great - only downside is when the light is at certain angles the nail hole [ though filled] can be seen.

Can upload pix if you are interested.

Regards,
Bob

I'd love a pic as I'm considering similar ...

Pix as requested, the flash does "highlight" the nail holes - far more than natural light. There wasn't much else I could do as any form of skew nailing or secret nailing caused the nails to either split the timber and/or bend the nail up like a pig's tail. I didn't do it on my own but had help from a builder mate who had the nail gun etc.

Regards,
Bob

Quote:

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Originally Posted by Bob38S

Just last year we finished our entire ceiling with T&G type [just on 1600 metres] - the original plaster ceiling was not glued at all and was sagging between the screw fixings - we have an exposed step where they actually join [can't really recall the actual profile name] - the reason being that should they "gap" it would not be as visible.

As the trusses were 25 year old [very] hardwood - we had to nail through the faces - 7000+ nails - we also used a "sausage" type of fixing glue to run along at each fixing point.

The finish was dimension 4

It looks great - only downside is when the light is at certain angles the nail hole [ though filled] can be seen.

Can upload pix if you are interested.

Regards,
Bob

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i believe the term is "shiplap"

So what's the consensis? Will they cup if not nailed on more than the tongue?

The Australian standard for flooring requires that any board width greater than 85mm not use hidden nails.

See the attached link for some other flooring information, including nail size.

Kev,

Does this also apply to ceilings? Each board covers approx 130mm

OBBob,

We glued each plank as well as nailed - so far no cupping, shrinkage, expansion etc. Only been one summer so far - at times high 30's and some 40's - there are fibreglass batts above the ceiling - no real "feel" of heat when touching the ceiling on the inside.

NB - as we went from a relatively fire resistant ceiling [plaster] to a highly flammable ceiling - we now have smoke sensors in every room rather than a few strategically placed ones.

Regards,
Bob

Bob,
Not sure on ceilings, are you prepared to chance it?

G'day Kev,

No, we didn't chance it, if you check posts 5+7 you'll see that we had to go through the faces as the timber we were going into was too hard. Must admit though, we did try it, so through "good luck" we didn't make this "mistake".

Regards, and thanks,
Bob

Hi guys, i have a ceiling that might help - its pine (looks radiate to me, but could be cypress given the termite problems this house had, and the boards are 140mm wide with a v groove down the centre of each board - there are no visible fixings, so i assume a nail through each groove for hidden nailing - done 1984 so probably a 50mm t nail - its still standing except where i put my foot through it (Doh!), so tongue and groove wide boards seem fine, no idea for flush finished boards.

BTW, it is stained reddish brown, so no seal on one side.

Did you notice if it was glued as well ... maybe where you put your foot through??

If you go into the ceiling and look along the boards the ceiling is attached to you should see "squeeze out" of the glue on either side of the board - if glue has been used.