Thanks to all the great postings of designs for a deck extension I know now what I would like to do. I still have a question as to the materials, specifically the deckking to use.
1) What is the best wood to use for the decking?
2) Does it have to be treated? With what and how?
Anu and all advise is greatly appreciated. I just dont want to have to redo this project in a few years because the wood rotted away underthe carpet. Thanks again.
You don't have to use treated wood if you seal/coat it with epoxy resin or fiberglass. I used 5/8" plywood, coated with fiberglass resin, then a layer of fiberglass cloth and resin on both sides which gave me about a 7/8" thickness when completed.
Good luck with your project.
"I know something about a lot of things, and I know a lot about some things, but I don't know everything about anything." - DG
Is the fiberglass mesh needed? I thought that was only for strength. I read a lot of posts of people "painting" on a fiberglass resin thinned with acetone to waterproof the wood.
I did the fiberglass cloth for strength. It's not needed just to waterproof. You're correct about using the resin thinned with acetone to paint the wood.
"I know something about a lot of things, and I know a lot about some things, but I don't know everything about anything." - DG
Whats the best way to mix that? Do I have to use the hardener that comes with the epoxy? How many coats should I put on? Thanks for all the help so far. I want to be sure to do it right the first time and you are helping a lot.
No more than 10% acetone to polyester (fiberglass) resin. If you're using epoxy resin, I'm not sure how to thin it but I don't think you're supposed to use acetone. If using polyester resin, thin it first then apply the catalyst (hardener). Thinning it will probably take it longer to cure. I would probably do two coats.
I'm no expert and hopefully some of the others on this site will chime in with some answers.
"I know something about a lot of things, and I know a lot about some things, but I don't know everything about anything." - DG
Thanks for the advise. Is there a big difference between fiberglass and epoxy resin? Fiberglass resin is what I have seen the most of on store shelves.
I've personally never used the epoxy resin so I can't say for sure.
"I know something about a lot of things, and I know a lot about some things, but I don't know everything about anything." - DG
Do not use treated lumber. Resin will not adhere to it. Epoxy is better than polyester resin in just about every way. But those differences wont become apparent for many years. If you want something to get you by and is cheap, then poly will be fine. If your a perfectionist and want to use the best and have it last as long as possible then epoxy would be the way to go. You dont need to thin epoxy resin but if you think you have to, only thin the first coat and use 3 coats. If you put the resin on the wood late in the day as temps are cooling, the air in the wood is contracting and will draw it in. If you do it in the morning as its getting warmer, the air in the wood is expanding and will blow airholes in the surface.
Use polyester resin, you'll never see the benefit to epoxy and it is very expensive (upwards of $100 per gallon).
You don't need to thin the resin.
3 coats, sanded smooth between coats.
Lay out the cloth (dry) on the plywood, pour the mixed resin over it, squeegee it out until the cloth "disapears". Remove ever trace of pooling resin and air. Allow to set overnight. When you return wipe it down. You'll notice a brownish oil like substance. That's called blush and is normal. Clean it all off. Sand. 2nd coat, remove pooling, let set, clean blush off, sand. 3rd coat, repeat the routine, sand to perfection. After 24 hours it'll be ready for carpet.
I prefer doing 1 side of the wood and the perimeter edges and leaving the underside bare to allow it to breath (for decking only).
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