Building a Deck – Which Grinder for Cutting Trex?

Hey everyone! I'm about to start building a 12x16 composite deck (Trex). I need to cut the boards to size and also cut some metal railing posts. I don't own a grinder yet. Should I get a 4.5” or 7”? Corded or cordless? I'm on a budget but want something that'll last. What do you recommend?

For Trex, a 4.5” corded is plenty and you can get a decent one for $50-60. I've used a cheap Craftsman for years cutting composite and it works fine. Just get a diamond blade for composite and a metal cutoff wheel for the posts. Don't waste money on battery tools if you're not already in a system.

I'd go with a 4.5” DeWalt cordless if you already have batteries. I've used my DWE402 (corded) forever though. For composite, a nice Diablo blade makes all the difference. Also, a 7” is overkill for a deck build. Stick with 4.5” and it'll handle everything.

Gotta agree on 4.5”. But if you plan on more projects, consider a variable speed grinder. I have a Makita 9557PB and it's smooth for cutting composite without melting. Also, don't forget a dust shroud – Trex dust is nasty. Good luck!