Best Caulk for Cement Board Siding

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    LESLIE: Jeffrey in Wisconsin has a cement board siding question, you’ve got The Money Pit. How can we help you today?

    JEFFREY: Well, I’ve got cement-board siding and occasionally, a crack appears. And I’m wondering – I’ve tried a couple different caulks. The last one was QUAD. And it just kind of swells and shrinks with the weather and it shows after you paint it. Is there anything out there you could help me with to repairs cement board siding?

    TOM: What you want to use is a silicone caulk because it’s the most permanent one. It’s got good adhesion and expands and contracts. But you are correct that it is very difficult to paint. So what I would tell you to do is to use a colored caulk, to choose the caulk in the color of the siding. And this way, you don’t have to worry about painting it and you could still have the qualities of expansion and contraction and adhesion so it’ll stay put once you apply it. I mean cement-board siding does not need to be painted nearly as often as wood siding. So if you get the right color and you get it applied properly, you know, this is something that can be with you for 10 years.


    TOM: The product is available in many different colors. I see it on The Home Depot website in gray and tan and white, of course. And there is also something called “paintable silicone.” It’s a white silicone caulk but it’s paintable. It’s made by GE. It’s called GE Silicone II. So you have a lot of options to choose from.

    JEFFREY: Guess I’ll check that out, because what I’ve had so far hasn’t really done what I’ve been able to be satisfied with.

    TOM: Well, remember the secret to a successful caulking project is to make sure the surface is clean and dry when you apply it and make sure you give it plenty of time to set up. But I’ll tell you, if it’s done right, it’s pretty indestructible stuff.

    JEFFREY: OK. Well, thank you.

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