What Houston's April Rains Do to Your Window Seals and Siding

April in Houston doesn't ease into rain season. It arrives all at once — 4 to 6 inch events that hit fast and hit hard. Most homeowners think about their roof. But I spend just as much time at windows and siding, because that's where a lot of the real damage hides.

Window sealant fails quietly. You won't see a drip. You'll see a faint stain on the drywall below the sill or paint bubbling on interior trim. By the time that's visible, water has been getting in for a while. Even on new construction in Pearland and League City, I find improperly caulked window flanges more often than I'd like. New doesn't automatically mean sealed.

What I look for: separation between the window frame and exterior casing, caulk that's cracked or pulling away, and soft or discolored wood around the frame. A gap as small as 1/16 of an inch is enough for wind-driven rain to push water into the wall cavity. Under TREC standards, window sealing deficiencies are reportable conditions.

Fiber cement siding covers a huge number of homes built in the 2000s and 2010s across Friendswood and Webster. It's durable — but only when painted edges are maintained. Factory-primed fiber cement is not waterproof on cut edges. When April rain hits an unpainted cut edge near grade or a window opening, that board absorbs moisture, swells, and the joint opens. I've pulled back trim and found the OSB sheathing behind it soaked through.

Vinyl siding has its own weak point. Panels cracked at the locking channel — from hail, a lawnmower, or a pressure washer set too high — are invisible from the street but a direct path for water into the wall. I walk the perimeter slow and low, looking for any panel that doesn't lie flat or has lost its lock at the bottom.

The spots most homeowners miss are transition points — where siding meets a roofline, deck ledger, or window head flashing. Flashing has to overlap the siding below it and be sealed at the ends. When it's not, water runs behind the siding and into the wall framing. I see this regularly in Clear Lake and Seabrook, especially on homes with additions built years after the original structure.

If you want to do your own April check, walk the exterior after a rain. Look for water staining below windows or at wall transitions. Run your hand along the bottom of window frames and feel for soft spots. Check that caulk joints are continuous, uncracked, and adhered on both sides. Any separation is a repair that needs to happen before summer humidity makes it worse.

If you've got questions about what I look for on exteriors, or you want to schedule an inspection this spring, reach out.