Single-ply seam re-seal
Re-sealing the edge of a welded or bonded seam with the sealant the membrane names. Used where the seam has lifted but the weld underneath is intact.
Serving Bernalillo County
Membrane Seam Repair in Albuquerque, NM
Repairing the joints in single-ply and modified bitumen membranes on flat roofs in Albuquerque, with the sealant the membrane names.
- Roof repair and full replacement
- Leaks, hail and storm damage
- Flat and pitched roofs
Get a fast quote
Fastest: call (833) 751-2102. Or send this and we call you back.
Seam Repair
Membrane Seam Repair: what it covers
Quick answer
A seam is the joint where two sheets of membrane meet, and it is the most common place a flat roof opens. A roofer probes each seam, cleans and re-seals the failed ones with the product the membrane manufacturer specifies, and patches any split.
A flat-roof membrane is only as good as its joints. The field of the membrane is one continuous sheet, but the seams are made in the field, often in cold or wet weather, and they age faster than the sheet itself. When a seam opens, water finds the gap, and the first sign is usually a stain well away from the seam.
Membrane types differ in how their seams fail. A single-ply sheet relies on a heat-welded or solvent-bonded seam and a sealant at its edge. A modified bitumen roof uses lapped seams that are torched or bonded and then checked along their length. The repair is shaped by the material, and a roofer should name the membrane before the seam work is quoted.
This page explains how seams are probed and repaired, what goes wrong with each membrane type, and what the scope should say. The repair is a fix to the joint, not to the whole roof, and it is the part of a flat-roof job that needs the closest attention.
- Service area
- Albuquerque & Bernalillo County
- Availability
- Call to reach a local roofer
- Phone
- (833) 751-2102
Warning signs
Signs you need membrane seam repair
Seam work is done on a hot, flat surface with solvents or torches in some systems. Keep a fire extinguisher on the roof where torches are used, and do not stand on a seam while it is still soft.
- A seam that lifts at its edge when pressed or when a corner is pulled gently
- Dried, cracked or shrunken sealant along the edge of a seam
- A line of stain on the ceiling that runs straight, which often follows a seam
- Splits or pinholes at the seam edge where the membrane has aged
- A seam that has a visible gap or a 'fish mouth' where the two sheets have separated
- Bubbles along a seam line that move under foot in warm weather
Our process
How our membrane seam repair visit works
Identify the membrane and its seams
The roofer identifies the membrane type, as single-ply or modified bitumen, and the seam method used. The repair product is chosen to match that membrane and the manufacturer's detail.
Probe every seam by hand
Each seam is probed along its length, with pressure at the edges and the corners. A seam that moves, lifts or shows a gap is marked, and the marks are numbered on the roof plan.
Clean and prime the failed length
The failed length is cleaned of dirt and old sealant, and primed where the product requires it. The surface must be dry, and the roofer checks the weather before the work is started.
Re-seal or patch with the named product
The seam is re-sealed or a patch is laid over the split, using the product the manufacturer names. The patch laps the sound membrane by the distance the detail requires.
Test the joint and record the result
The repaired seam is tested by hand and the result is photographed. The record lists each seam by number, the repair made and the product used.
Which membrane fails at the seam first?
Single-ply seams fail where the sealant or the weld ages at the edge, and modified bitumen laps fail where the bond lets go. Both are common, and the roofer checks which applies.
Single-ply membranes are joined by heat welding or by a bonded seam, and the edge of the seam is often finished with a sealant. Over time the sealant dries and shrinks, and the edge of the seam begins to lift. A weld that is intact underneath can still leak at the lifted edge, which is why the edge is the first place to look.
Modified bitumen is joined by overlapping sheets and bonding or torching them together. The laps can open where the bond fails, and where a sheet has moved the lap can separate along its length. The repair is to clean the lap, prime it and re-bond it, which takes longer than a single-ply edge repair.
- Single-ply: check the sealant along the edge first
- Modified bitumen: check the lap bond along its length
- Both: note any seam that has moved with the structure
Why does a seam repair fail a second time?
Usually because the surface was not cleaned or primed, the product was wrong for the membrane, or the work was done in the wrong weather.
A seam repair that fails again is nearly always a surface problem. Dirt, old sealant or moisture under the new product stops it bonding, and the seam lifts again in the first hot spell. Cleaning to bare membrane, priming where the product requires it and working on a dry surface are the three steps that make a repair last.
The wrong product is the other common cause. A sealant that suits one membrane can fail on another, and the manufacturer's product list is the reference. The roofer names the product in the scope, so you can check it against the manufacturer's detail.
- Clean to bare membrane before any product goes on
- Use the sealant or primer the manufacturer names
- Work only on a dry surface in the right temperature
When is a seam repair not the right answer?
When the seams are open across most of the roof, or when the membrane has become brittle and splits when lifted.
A seam repair is the right answer for a roof where the seams are the problem and the membrane is still flexible. If the seams are failing across most of the roof, or if the membrane cracks when it is lifted, the seams are not the cause but a symptom. The roofer should say so in writing and explain whether the roof is near the end of its life.
A test of flexibility is one way to see this. A sound membrane stretches and springs back. A membrane that cracks or powders under the hand is aged, and repairing it piece by piece only moves the leak to the next seam.
- Seams failing across most of the roof
- Membrane that cracks when it is lifted or flexed
- Repeated repairs that move the leak to a new seam
How do you keep a seam from opening again?
Inspect the seams after each large storm, keep the edges clean of grit and standing water, and act on the first sign of lifting rather than waiting for the stain.
Seams last longest on a roof that is looked after. After a large storm, walk the roof edge and the seam lines from the safe side, looking for lifted edges, grit trapped under a seam and water that stands along a line. A seam with grit under it is a seam that will lift, so the grit is brushed away when it is found.
Ask the roofer to mark the seams on the roof plan at the first visit. A numbered plan lets you and the roofer compare the seams from one inspection to the next, and it shows where the repairs have been made. A seam that keeps appearing on the list is the seam that needs a different repair, not another coat of sealant.
- Look at the seam edges after a large storm
- Brush grit from under a seam before it lifts
- Compare the numbered seam plan at each inspection
Options
Types and options for membrane seam repair
Modified bitumen lap repair
Re-bonding or torching a lap that has opened on a modified bitumen roof, with the lap cleaned and primed first. More labour than a single-ply repair because the lap is longer.
Split and patch
Covering a split across a seam with a patch of the same membrane, laid with its edges sealed. Needed when the membrane itself has torn rather than the seam alone opening.
Bernalillo County
Why membrane seam repair is different in Greater Albuquerque
FACTS.md notes hail reports near the metro, and a seam check is worth booking after a large storm, because hail and wind can pull a seam edge without cutting the membrane.
The FACTS sheet gives no sourced roof-type share, so this page does not claim how many flat roofs in the city use each membrane type.
Seams on buildings in the outlying towns are worked on the same way. The travel and access decide the quote.
Still stuck? We pick up 24/7.
If it's an emergency, call now. For non-urgent membrane seam repair, send the form and we'll call you back.
Where we work
Membrane Seam Repair across Bernalillo County
- Seam Repair in Albuquerque
- Seam Repair in Rio Rancho
- Seam Repair in Kirtland AFB
- Seam Repair in Corrales
- Seam Repair in Isleta
- Seam Repair in Bosque Farms
- Seam Repair in Cedar Crest
- Seam Repair in Placitas
- Seam Repair in Peralta
- Seam Repair in Bernalillo
- Seam Repair in Sandia Park
- Seam Repair in Tijeras
- Seam Repair in Los Lunas
- Seam Repair in Tome
- Seam Repair in Edgewood
- Seam Repair in Algodones
- Seam Repair in Belen
- Seam Repair in Torreon
- Seam Repair in San Ysidro
- Seam Repair in Laguna
- Seam Repair in Moriarty
- Seam Repair in Santo Domingo Pueblo
- Seam Repair in Estancia
- Seam Repair in Cerrillos
Not sure if you're covered? Check your ZIP code.
Related
Related services
Flat and Low-Slope Roof Repair
Repairs to flat and low-slope roofs in Albuquerque and the towns around it, starting with where the water sits and why.
Roof Flashing Repair
Repairing the flashing at walls, chimneys, skylights and vent pipes on pitched and flat roofs in Albuquerque and the towns around it.
Elastomeric Roof Coating
Coating a sound flat or low-slope roof in Albuquerque to extend its life, after an inspection shows the substrate can take it.
Guides
Read before you book
A Flat Roof Checklist for After a Storm in Albuquerque
After a storm a flat roof can be checked from the ground and from inside the building.
FAQ
Membrane Seam Repair FAQs
How do I tell a seam leak from a flashing leak?
A seam leak usually shows as a straight stain under the membrane's line, while a flashing leak tends to appear at a wall, a vent or a drain. The roofer checks both.
Can a seam be fixed in the rain?
No. Sealants and primers do not bond to a wet surface, and the repair would fail. The roofer books the work for a dry period.
Does a seam repair affect the membrane warranty?
It can, depending on the manufacturer and the installer. Ask for the warranty terms in writing before the work is booked.
How long does a seam repair last?
It depends on the membrane and the cause of the failure. A well-prepared repair with the right product lasts a long time, but the roofer cannot promise a period without seeing the roof.