Paint Wood Trim or Cap with Aluminum
When discussing whether to cap your wood trim or paint it, quality is the biggest factor. A big part in this decision is the quality of work you intend to buy. And quality is particularly important when you’re painting the outside of your home.
The quality of capping work isn’t such a big factor. That’s because if it looks good when they leave, you’re probably alright, but there are still some caveats.
Not so with painting though, quality of the work performed is everything.
Painting the Trim
I’ve been seeing a lot of pro painters not using primer on the exterior of a house, very bad. One painter who told me “The paint can says it contains primer so why should I have to primer”? Ah, because it’s the right way to do it! He also went on to tell me that the paint store, Sherwin-Williams, told him that he should put on a primer coat, but he doesn’t do it. So, you get a more competitive quote but inferior work. But that’s not all what we’re talking about here.
Painting is simple, get the wood down to a sound surface, cover at least bare wood with primer. Then you put on 2 topcoats. The wood has to be in good shape to do this though. If there is rot or mold it has to dealt with before the paint goes on. You’ll have to replace or repair rotted boards. If you do it right it should last for 20 years. Aluminum capping on the other hand may last much longer than that. But there can be issues down the road.
Pros and Cons of Capping
Aluminum has to be nailed to sound wood. If it’s not, guess what, it will come loose and let water in. This situation will cause the wood to rot under the capping. And it will rot even faster than painted wood because the moisture is trapped behind the capping. Also, painters caulk might only be good for 10 years. But the best siding sealant, Quad (or similar oil based sealant), will last for much longer. If the sealant cracks or peels off, the siding is no longer water tight.
Many older homes have some very nice trim boards, particularly around windows, and to cap them over reduces the beauty of the original design. But that fancy molding design is dated now, so unless you’re trying to preserve architectural details, aluminum might be okay too.
Cost of Painting vs Trim
One last factor is cost. It might cost you 2 times as much to cap all your trim boards than painting them. It takes longer to bend the metal to just the right shape. But aluminum capping can truly be much less trouble over time. However, if the aluminum siding is properly “caulked” with sealant then there shouldn’t be any real problems down the road.
Dry, Sound Wood Always
But whether capping with aluminum or painting the wood trim, there is one thing to remember. In either case the wood should be dry and in good shape before doing the work or the results may not last for as long as you hoped.
I do this kind of work also, please see my Repairs page for details.