TSP - yes or no ???

[zxcvbob]

If you wash the wood with water, it will raise the grain as it dries. I think that would make the paint stick *better*.

You'd only need to sand it after washing (and then go over with tack cloth) if you were gonna varnish it and try to get a fine finish.

Best regards, Bob

[George E. Cawthon]

Yes, porches and decks tend to be an exception since they are often heavily weathered and a fair degree of roughness should not be a problem. And I presume the really dirty areas are the deck. If I were you, I would get a regular scraper with a

3" wide blade and scrape any loose or blistered areas, hand wash any really dirty areas with any good detergent, then power washing with TSP, then powerwash with clear water, which will probably lift more areas of paint. Let dry thoroughly and scrape the edges of any paint to bare wood to feather the edge.

Make sure that you powerwash solid wood, not manufactured stuff or plywood.

Since you already have everything painted you probably have no option but to repaint, i.e, an oil stain on the deck would not be an option unless all paint were removed. So, when the wood is thoroughly dry put on a good undercoat, then paint with a product designated for porches and decks. Personally, I would use oil paint and top coat with two layers of paint. BTW, I don't know where you live, but a porch in most areas should not have that much paint damage in just 8 years.

I don't have a favorite book on just painting, probably any book at Lowes or Home Depot would be fine.

[Phisherman]

For exterior wood. Dissolve 1/2 c. TSP in 1 gallon warm water, add 1 cup household bleach, add to a garden sprayer. Use a brush with a long handle, rubber gloves, boots, old clothes, eye protection, and garden hose. Wash one section at a time. Rinse twice using a nozzle set to a fan spray. If the deck is really dirty, you may need to wash it twice. A pressure-washer will work too, although you can damage the wood. Allow the wood to completely dry before you paint or stain--perhaps a week. Repair any damaged areas, set nail heads, etc. You can use "JoMax" instead of the TSP.