t&g or shiplap?

[sailor1313]

Would it be possible to use a ship lap joint instead of t&g? It could be formed with 2 quick passes oon a table saw or even jigged up to do with a skil saw. You'd still end up with an overlapping joint.

[Kama]

You would end up with an exposed nail somewhere, but you could counter-sink the head and plug it. I suggest using screws instead of nails too, because you won't be going in at an angle any longer. You'll have to recover some of the strength that angled nail gives to the joint.

If you do this make sure that you get the plug FLUSH, even slightly beneath the top of the floor is ok and soften the edges of the plug. The reason is this: When winter comes, your flooring will shrink, but the plug will not. That plug is going to stand proud of the floor and your going to rip the bottom of your foot on it. It does not feel good.

Andy

[hawkiye]

Don't see why it wouldn't work.

Why would you end up with an exposed nail or screw? If you nail in the joint then place the over lap over it,that will hide it? Am I missing something?

Blayne

[ChainsawGrandpa]

Shiplap should work just fine. Just remember to only use
quarter sawn wood.
-Rick

[hawkiye]

Don't see any advantage to quarter sawn. Seems to be a matter asthetics and personal preference in my view. Personally I prefer the variation in plain sawn over the more uniformed look of quarter sawn.

You could probably get away without T& G or Ship Lap and just butt straight edge boards together since it is really the ceiling and the actual roof will be plywood or what ever on top of sleepers and then weather proofed.

I like the ship lap idea though especailly if one is considering cutting the lap themselves

Blayne

[Ellsworth]

Shiplap should work just fine. Just remember to only use
quarter sawn wood.
-Rick

I believe Rick is expressing a concern about 'cupping,' which could indeed cause some problems especially on a floor. Plain sawn will also shrink and swell a lot more than quarter sawn.

For some background about that check out

http://www.allwoodwork.com/article/woodwork/plainorquartersawn.htm

http://www.hoganhardwoods.com/hogan/pages/technical/Technical_01/lumbersawing_01.htm If you look at the cross section drawings on this site you should be able to see why plain sawn lumber tends to cup

[hawkiye]

I believe Rick is expressing a concern about 'cupping,' which could indeed cause some problems especially on a floor. Plain sawn will also shrink and swell a lot more than quarter sawn.

For some background about that check out

http://www.allwoodwork.com/article/woodwork/plainorquartersawn.htm

http://www.hoganhardwoods.com/hogan/pages/technical/Technical_01/lumbersawing_01.htm If you look at the cross section drawings on this site you should be able to see why plain sawn lumber tends to cup

Well yeah if your going to mill your own wood and air dry it. But if your going to buy it, it is kiln dried and will work fine and be cheaper. Still if you mill it yourself and have time to air dry it you have to stand it on end while it dries and keep it out of the sun and have good air circulation but that could take a year or more..

I assume most folks are going to buy roof and floor lumber.

Blayne

[Kama]

To answer your question, let me ask you a question: how would you keep the side of the 2nd board down that overlaps the first board?

With T&G the bottom part of the groove does this. There is no bottom part with shiplap. I wouldn't trust any adhesive either, without clamping, and what a mess to clean up.

Andy

[hawkiye]

http://www.homestore.com/hs_media/images/homegarden/homeimprovement/howtos/howtos/chrep191fig1.gif

You toe nail or screw in the joint under the lap just like tongue and groove. Wer'e talking a ceiling here so it really doesn't matter of you were to face nail or screw. In a floor it would be different. As you would want to make sure the lap could not rise which would require face nailing or screwing.

Blayne

[Kama]

I thought we were talking about both the floor and ceiling.

Anyhow, wood will always have movement no matter how it is dried. That is why doors have floating panels, instead of glueing it to the frame. When installing new laminate/ engineered flooring you leave at least a 1/4" gap around the perimeter. Doors and windows can stick after a rain. On bread board ends and for tables, you should elongate your holes etc... This is just as painful a lesson to learn as slidding your foot across the plug that is standing proud because of seaonal movement.

Not all woods have the same properties, so they move more or less than others. It depends on how much moisture the wood absorbs or releases. The softer the wood, the more moisture it will absorb and the more movement you'll have.

Quatersawn lumber doesn't have as much movement, but is more expensive because you get less yeild from your timber. The majority of the movement is along the width and some in the thickness. There is no movement in the length.

When I install shiplap, I nail thru the bottom part of the top piece so that it goes thru both pieces. Getting a call back because the shiplap you just put up, blow off during it's first NorEasterner is a little embarrassing and doesn't pass your name on in good light.

Andy

[hawkiye]

When I install shiplap, I nail thru the bottom part of the top piece so that it goes thru both pieces. Getting a call back because the shiplap you just put up, blow off during it's first NorEasterner is a little embarrassing and doesn't pass your name on in good light.

I would agree if your using shiplap as your final outside coating on the roof or siding etc. As I said for a ceiling such as the open beam type on a log home that will have sleepers and a roof on top it really is not that big of a deal.

Blayne