What Arizona Summer Heat Does to Your Doors, Seals, Caulk and Paint

How Sun and Heat Age a Home

Ultraviolet light breaks down the chemical bonds in paint, caulk, plastics and rubber. Over time, surfaces fade, chalk, crack and become brittle. South and west facing walls take the worst of it.

Heat makes materials expand during the day and contract at night. Over many seasons, that movement opens gaps at joints, loosens fasteners and cracks rigid materials. Wood dries out, warps and splits.

Low humidity pulls moisture from wood, caulk and weatherstripping. Items that were flexible become stiff. That is why a bead of caulk that looked fine a few years ago may now be crumbling.

Dust is the other constant in the desert. Fine dust works into hinges, tracks and weatherstripping and wears them down faster. A periodic cleaning of door and window tracks, with a light lubricant where the manufacturer recommends it, keeps moving parts working.

Doors: Warping, Sagging and Sealing

Exterior doors that face the afternoon sun can warp, bake their finish, and swell or shrink with temperature. Watch for a door that rubs at the top, drags at the bottom, or no longer latches without a push.

Hinges loosen over time. Tightening hinge screws, or replacing short screws with longer ones that reach the framing, solves many sagging doors. Planing an edge or adjusting the strike plate fixes others.

Door finishes take a beating. Peeling or blistered paint or varnish on a south facing door should be sanded and refinished before bare wood is exposed. Once the wood is exposed, the damage accelerates.

Keep an eye on the threshold too. Aluminum and wood thresholds under a sunlit door expand and contract, and the sealant beneath them can crack. A cracked seal under a threshold lets water and dust track into the house, so re-sealing it is a quick and worthwhile fix.

• Door rubs or sticks in the afternoon heat
• Daylight visible around the edges when closed
• Peeling or blistered finish on the sun side
• Loose hinges and a door that sags

Weatherstripping and Door Sweeps

Weatherstripping is rubber, foam or vinyl, and it is one of the first things to fail in the desert. Cracked, flattened or missing strips let hot air, dust and insects in and make the air conditioner work harder.

Replacement is usually quick. Remove the old strip, clean the surface, and install new weatherstripping sized for the gap. Door sweeps on the bottom of doors wear down from friction and sun, and they should be replaced when they stop touching the threshold.

Do the same for garage doors, where bottom seals shrink and crack. A good seal helps keep out dust during haboob season, and it keeps cooled air in during summer.

Do not forget garage door seals and the gaps around the door frame. Heat and sun shrink the rubber, and a gap along the bottom invites dust, insects and hot air into the garage.

Caulk Around Windows and Trim

Caulk is not permanent. In this climate, it can dry, shrink and pull away from the surface within a few years. Look at joints around windows, door frames, trim, and where stucco meets other materials.

Remove old caulk fully before applying new, then clean and dry the joint. Use a caulk rated for exterior use and UV exposure, and follow the label for application temperatures. Applying caulk in extreme heat can cause it to skin over too fast, so early morning is a better time.

Inside, bathroom and kitchen caulk can fail from moisture rather than heat. Check around tubs, showers and sinks.

Window frames and sliding door tracks collect baked-on dust and grit. Vacuum them, wipe them down, and check that weep holes are clear so rain can drain out instead of pooling inside the frame.

Exterior and Interior Paint

Exterior paint fades and chalks first on sun exposed walls and trim. Run your hand over a wall. If a chalky residue comes off, the paint is breaking down. Cracks and peeling mean it is time to prepare and repaint.

Preparation matters more than the paint itself. Scrape loose paint, repair cracks, prime bare spots and caulk joints before painting. Paint applied over a failing surface fails again.

Indoors, sun through windows fades walls, furniture and flooring. Window film or shades can help, and so can painting rooms with a washable finish where sun hits.

Choose paint products designed for strong sun exposure, and ask a paint supplier about finishes suited to desert conditions. Lighter colors tend to reflect more heat than very dark ones, though HOA rules may limit your palette.

Other Heat Related Wear

Garage door springs and rollers, sprinkler parts, plastic fixtures and outdoor lights all age quickly. Plastic light covers and sprinkler heads become brittle and crack. Check them each spring.

Wood fences and gates dry and split, and fasteners loosen. Re-staining or sealing wood regularly helps. Inspect posts and latches for movement.

Pay attention to the attic and the air conditioning system. A hot attic is normal, but excessive heat or poor insulation can make rooms uncomfortable. Have the AC serviced by a qualified technician.

Hose bibs and exposed pipes can also suffer in the sun. Check for cracks in plastic fittings, and look for slow drips that waste water and stain surfaces below.

A Simple Yearly Routine

Pick a cooler month, like October or March, and do a walk-around. Check caulk, weatherstripping, door sweeps, paint, fence and gates, and light fixtures. Make a list and group the repairs.

Doing small repairs yearly costs less than dealing with water intrusion or rot later. Charme and Sons handles these seasonal maintenance items across Peoria, Surprise and Sun City, so you can get several done in one visit.

Keep a simple log with the date and a note for each repair. After a couple of years you will know exactly how long your caulk and paint last on each side of the house, which makes planning easier.