Q: I recently had redwood siding replaced on one side of my house. The three other sides are also redwood, which has weathered and grayed. Eventually, they will also need new siding. How do I get the new siding to look like the old siding? What do I use to protect the siding from sun and rain?
A: Unless you want to use paint, it’s virtually impossible to match old and new siding.
Redwood, like all woods, changes color as it ages because of ultraviolet rays, the rate at which the wood loses moisture and exposure to weather.
This color change is not uniform. Different areas of the siding, indeed different boards, age at different rates. If you chose to seal or stain your home, the best you can hope for is to come close to a match, but we’re pretty sure we’d be unhappy with the result of any attempted match.
If you want to try for a match, let the new siding age until it starts to gray. This could take several years. Sand, then brush the siding with a stiff bristle brush or broom to remove any accumulated dirt or dust. Then apply a good wood sealer or transparent stain. It will take at least two coats, and probably three or more.
Be sure to try a sample on an inconspicuous place on the old siding and the new siding to see if you like the way they match up. If you’re OK with the test result, complete the job.
Two other alternatives, which we believe would produce better results, are either to apply a semitransparent stain or to paint the house. Staining will give you a better chance at an acceptable match, while painting will ensure that the color of all four sides of your house will be the same. We recommend you paint your house rather than seal or stain it.
Based on your description, the siding is in pretty sad shape. We can only imagine the condition of the redwood. It’s probably checked and split and will require a lot of surface preparation for a good paint job. That’s the bad news.
The good news is that with thorough preparation, you may be able to salvage your existing siding. An added benefit to painting is that you do not have to wait, and in fact should not wait, for the new siding to age.
Because redwood is soft, it sands easily. It is also resistant to pests and fungus. So we’re betting that the siding is pretty sound and a thorough sanding will bring it back to a point where it will accept paint well.
Normally we’d recommend you pressure-wash the siding, but not in this case. The bare wood is too soft and will accept water too easily. Brush the siding with a stiff bristle brush or broom to remove all the sanding dust.
Apply a good coat of oil-based primer and add some boiled linseed oil to the primer to enhance penetration and to add some much-needed moisture to the wood. Caulk all joints and splits in the wood with a good acrylic caulk. Finally apply two coats of a good acrylic latex finish.
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