Las Vegas roofs are built for sun more than rain. Most of the year that's fine. Then the monsoon arrives, and a roof that has quietly baked for months suddenly has to handle wind-driven rain and powerful gusts. The Clark County Regional Flood Control District sums up the local weather well: in Southern Nevada it hardly rains, but when it does, it pours. Its flash flood guidance notes that July through September can bring sudden downpours. A little preparation in late spring can keep a storm from turning into a ceiling stain.
Know the season
The National Weather Service defines the Southwest monsoon season as June 15 through September 30. In its climate summary for Las Vegas, NWS notes that monsoon thunderstorms typically come in July and August, often developing over the surrounding mountains before moving into the valley. Gusty winds from these storms occasionally cause damage, and heavy rain can cause flash flooding.
NWS lists the main monsoon hazards as flash floods, downburst winds, lightning, dust storms and extreme heat. A Severe Thunderstorm Warning, according to NWS, means winds of 60 mph or more are possible. That's strong enough to lift roofing materials and send yard debris flying.
Prep by roof type
Concrete and clay tile roofs
Tile roofs are a familiar sight across the valley, and tile is durable, but the tile isn't what keeps water out. The underlayment beneath it does that job. Years of desert heat can wear underlayment out even while the tiles look fine from the street.
- Look from the ground (binoculars help) for cracked, slipped or missing tiles
- Watch for tiles out of line along ridges and hips, where wind loads are highest
- Ask a roofer to check the underlayment's condition if the roof is older or has had leaks. See tile roof underlayment
- Avoid walking on tile yourself, since it can crack underfoot
Asphalt shingle roofs
- Look for lifted, curled, cracked or missing shingles, especially at edges and ridges
- Check for granules collecting at downspouts, a sign of aging shingles
- Make sure ridge caps and starter strips are intact, since wind often starts lifting there
Flat and foam roofs
Low-slope and foam roofs depend on water draining off quickly.
- Clear roof drains, scuppers and canales of dust, leaves and debris
- Look for ponding areas where water sat after the last rain
- Check the foam's protective coating for wear, cracks, blisters or bare spots
- Inspect seams and flashing around HVAC units, evaporative coolers and other penetrations
Our foam roofing page covers recoating and repair.
Drainage: give the water somewhere to go
When CCRFCD says it pours, it means a lot of water in a short time. On the roof and around it:
- Clean gutters and downspouts, and make sure downspouts discharge away from the foundation
- Keep scuppers and drains on flat sections clear
- Check that yard grading carries water away from the house
- Trim tree branches that hang over the roof and could drop debris into drains or break off in high wind
Don't forget the attic
Many roof leaks start small and show up first in the attic, not on the ceiling. After the first real rain of the season, take a flashlight into the attic if it's safe to access. Look for damp or darkened decking, wet insulation, water trails on rafters, or daylight showing through. Note anything you find with a photo and its location. A roofer can trace a leak much faster when you can show where the water appeared.
Secure the extras
Downburst winds don't just hit roofing materials. They pick up whatever isn't tied down. Before the season, check that solar mounting hardware, satellite dishes, vent caps, patio covers and shade structures are secure, and store or tie down loose patio furniture and yard items.
During a storm
- Stay off the roof. Lightning, wind and wet surfaces make it dangerous.
- Stay away from flooded streets and washes. CCRFCD and NWS both stress that flash flooding is a serious danger.
- If water comes through a ceiling, move belongings, catch drips, and keep people clear of any sagging drywall.
After a storm
- Look from the ground first. Check for debris, displaced tiles or shingles, and bent flashing or vents.
- Check inside. Look at ceilings, the attic and around skylights for new stains.
- Photograph and date everything for insurance and for repair bids.
- Call a licensed roofer for anything suspicious, and ask about temporary protection if there's an active leak.
- Verify before you hire. Look the roofer up on the Nevada State Contractors Board license search and confirm an active license with a roofing classification. See our guide to avoiding storm-chaser roofers.
Related: monsoon storm damage · roof inspection · roof repair
Get your roof checked before the storms
We're an independent referral service, not a roofing contractor. We can connect you with a participating local roofer serving the Las Vegas Valley for a pre-season inspection or storm repairs. Call (702) 935-6742 or use the form on this page.
Sources
- National Weather Service, Monsoon Safety
- National Weather Service Las Vegas, Climate of Las Vegas
- Clark County Regional Flood Control District, Flash Flood Safety
- Nevada State Contractors Board, License Search
Information current as of the sources' publication. Rules, fees and recommendations can change, so confirm details with the agency or a licensed professional.