Wood Preservatives

[John Martin]

I want to put a preservative on the siding of my house. House is roughsawn white cedar clapboards, garage is roughsawn pine board & batten. When built 24 years ago they used bleaching oil on it, which gave it a somewhat gray color. All of it has since weathered to just about the color I want, so I'm not interested in stain.

I do want to preserve it, though. There are a few places where splashback from rain causes some particular problems, indicating it might need some special treatment. Generally, though, I want to do all the siding.

Growing up, we used creosote. The last time I went to buy some I found it hadn't been sold for years. Plus, it's black and smells and really isn't what I'd want on siding. Instead I bought green Cuprinol. Good protection, but still not a color I'd go with for siding.

I've heard of Penofin which sounds good, but at $40 per gallon and coverage on rough wood in the neighborhood of 100+ square feet per gallon, it seems a bit pricey.

Any recommendations?

John Martin Cumberland, Maine

[Lloyd E. Sponenburgh]

Zinc or tin napthenate; colorless, antifungal, not terribly expensive. Water soluble, though, so get the sort that's in a varnish or oil vehicle.

LLoyd

[kfvorwerk]

[stans4]

Lots of deck, siding and fence finishes out there, the more you pay, the longer they last. You can either get stain versions or clear versions, since you want that weathered look, get the clear. You can buy UV protection or not, depends on whether you want it more grey or not. It's common item at the big box home improvement places, have whole aisles full of different types here up to 5 and 10 gallon buckets. Apply with a brush or by spraying. Be careful with any rags afterwards, they're all drying oil hazards. Olympic was the brand I used on my trailer. Runs right around $20/gal, how much it covers depends on how porous your wood is and how rough the surface is. Ain't none of it going to be cheap. You aren't going to find coal tar derivatives for $4/gal that'll cover 1000 square feet/gal anymore, no matter how hard you try. Any other stuff is either going to be black like tar or green with copper salts, both types meant for buried wood, not siding. And I've read somewhere they want to ban the copper stuff, too.

Stan