Flat roof replacement in Long Beach, CA

A flat roof is never truly flat. A good one has a slight pitch, usually a quarter inch per foot or more, that walks water toward a drain, scupper or gutter. When an old roof sags, gets buried under layers of patching, or loses its surface to the sun, that pitch stops working and water sits. Standing water finds every seam, and the leak often shows up far from where it starts.

Our crews replace flat and low-slope roofs on homes, garages, additions, apartment buildings and small commercial buildings across Long Beach. This page covers what replacement involves and how we choose among the main membranes, each of which has its own page.

Five flat roof systems and where each one fits

There is no single best flat roof. The right system depends on how the roof drains, how much foot traffic it sees, what sits on top of it, and how long you plan to own the building. These are the five systems we install most often in Long Beach, with the job each one does well.

A cheaper system on a roof with poor drainage can cost more over time than a better-matched one, because ponding ages some materials much faster.

• TPO: a white single-ply sheet with heat-welded seams, reflective and popular on homes and commercial roofs that need a cool surface
• PVC: a single-ply sheet like TPO but more resistant to grease, chemicals and long ponding, often used over restaurants and tight drainage
• Torch-down: layers of modified bitumen fused with a torch, tough under foot traffic and around odd shapes
• Hot mop: traditional built-up roofing of felt and hot asphalt, finished with a cap sheet or gravel, still common on older Long Beach buildings
• Spray foam: a sprayed insulating layer with a protective coating that fills low spots and seals around many penetrations

Tear-off or roof-over: what the existing roof tells us

Many Long Beach flat roofs carry two or three old layers. Building rules limit how many roof layers can stack up, and every extra layer hides wet insulation and soft decking. We core-cut small test samples to count layers and check for trapped moisture before we recommend anything. If the old roof is wet, it comes off, because a new membrane sealed over damp material blisters and rots the deck from below.

A roof-over can make sense when there is a single dry layer and a compatible system, such as spray foam or a coating over a sound surface.

Drainage decides how long the new roof lasts

Most flat roof failures we see start with water that does not leave. We look at where water collects after rain or a hose test, how scuppers and drains are sized, and whether the parapet walls trap water against the roof edge.

The fixes are physical: tapered insulation boards that build slope back into the roof, crickets that split water around rooftop units and chimneys, enlarged scuppers, new drain bowls and overflow outlets.

• Tapered insulation to add slope where the deck sags
• Crickets behind HVAC curbs, skylights and chimneys
• Wider scuppers and new downspout heads at parapets
• Replacing rusted drain bowls and clamping rings

Questions we ask before recommending a membrane

We start with how the roof is used. A garage roof nobody walks on needs less than a roof with three condensers and a technician visiting monthly. Planned solar panels also change the system we suggest.

Then we look at energy and code. California's Title 24 energy code can require cool-rated roofing on some low-slope re-roofs depending on the climate zone, so we check what applies to your roof before ordering material. We also note which systems can be recoated later instead of torn off again.

When to call about flat roof replacement

Flat roofs across Long Beach, from Rancho Estates to the port

Long Beach has more flat and low-slope roofs than most people expect. The Cliff May ranchos in Rancho Estates were built in the 1950s with low-slope and flat roofs and wide eaves. Post-war ranch homes in Los Altos and the Plaza often have flat rear additions and carports. Downtown, Alamitos Beach and Ocean Blvd are full of parapet-roof apartment buildings, and older commercial roofs line Long Beach Blvd and the port area.

Weather here is hard on flat roofs in two ways. Long dry summers and strong UV bake membranes until they crack, and then winter atmospheric-river storms dump days of rain at once, which is when weak drains are exposed. The City of Long Beach requires a building permit for re-roofing, and cities outside Long Beach have their own building departments, which we work with from our Long Beach and La Mirada offices.