Another deck question

[LightningBG]

I'm far from an expert but laying it parallel to the house seems like a bad idea to me, expecially for something this wide. You'd have to slant it an awful lot to get the water all the way off and you'd be dumping an awful lot of water into that area. If you slanted it 'against the grain' to the short dimension the water would have to 'jump' the cracks and I think that would be a hassle. On a version of This Old House Tommy had it going the shortest distance and away from the house.

I think you missed something here.... there isn't any slanting to get water all the way off the ends. And there isn't any jumping cracks. The goal is to get it to drain through to the underside and hit the soffit underneath.

[LightningBG]

According to deck building software, they suggest having a center support (cantilevered)on the 12ft width even if you are using 2x8. I'm not sure about 2x10.

[CAMAN]

I think you missed something here.... there isn't any slanting to get water all the way off the ends. And there isn't any jumping cracks. The goal is to get it to drain through to the underside and hit the soffit underneath.

You will be asking for trouble if you are going to rely on the water draining through the tongue and groove. Over time the groove side shrinks and squeezes the tongue inserted into it creating a fairly water tight seal. Its the nature of all plastics. I wouldn't want to trust it to drain all the water from the deck.

[LightningBG]

You will be asking for trouble if you are going to rely on the water draining through the tongue and groove. Over time the groove side shrinks and squeezes the tongue inserted into it creating a fairly water tight seal. Its the nature of all plastics. I wouldn't want to trust it to drain all the water from the deck.

Fair enough. In that case, I would ditch the idea of tongue and groove and stick with regular composite decking, save some cash too.