TPO Roofing Replacement for Aging Membranes and Older Flat Systems
TPO replacement covers two jobs: a TPO roof that has reached the end of its life, and an older gravel, tar or modified bitumen roof being converted to TPO. Both start the same way, by finding out what failed and how much of what’s underneath is still dry.
Veteran BuiltCypress, Texas
Aging TPO tells you it’s done in a few ways. The surface chalks and crazes, the sheet shrinks and pulls at walls and curbs until the flashing tents away from them, and in places the reinforcing scrim starts to show through. Seams that were welded well can still let go where the original crew ran the welder too cold, and those failures tend to show up together across a roof rather than one at a time. A roof at that point can be patched for a while, but every patch is welded to a sheet that’s getting harder to weld to.
Converting an older roof is the other half of this work. Built-up gravel roofs and modified bitumen are heavy, dark and full of seams that have been mopped and patched for years. Moving to TPO means removing the old surface or, where the old roof is dry and code allows another layer, installing a cover board and new insulation over it. Gravel always comes off; nobody can weld a membrane over loose stone.
Either way, the new roof is only as good as the edges and penetrations it inherits. Old pitch pans filled with cracked sealant get replaced with welded boots or new curbs. Drains get new clamping rings. Parapet walls get the membrane run up and over, under new coping metal, because a parapet top that lets water behind the membrane will wet the insulation from above. Houston’s long cooling season makes the change from a dark roof to a white one noticeable for many buildings, though how much depends on the insulation and the equipment below.
On the Gulf Coast the weather writes most of the work orders. Hail in March and April, tropical storms later in the year, and a long hot summer that bakes a poorly vented attic. We check decking, ventilation and every penetration, because the roof surface is only one part of whether a roof is still doing its job.
The straight answer on tpo roofing replacement
Here is when we would recommend it, and when we would talk you out of it.
- Your TPO is shrinking away from walls and curbs, or the scrim is visible across large areas.
- A gravel or modified bitumen roof keeps leaking at seams and old patches, and the building below is cooled most of the year.
- Seam failures are turning up in several places at once, which points to the original welding rather than bad luck.
- A single puncture or one loose seam on a TPO roof that’s otherwise flexible is a repair, and replacing the whole sheet would be selling you a roof you don’t need.
- If the old roof is soaked through, a recover over it is off the table, and anyone offering one is trapping water under your new membrane.
- If you’re not sure what’s up there, start with a commercial roof inspection before asking anyone for a replacement price.
How we run it
- I
Probe and sample
We check seams and take core samples to see what’s under the membrane and how much of it is wet.
- II
Remove or prepare
Failed or wet material comes off; where a dry roof stays, a cover board goes over it so the new membrane has a clean base.
- III
New TPO and welded details
The new sheet is attached, welded and probed, with new boots, curbs and drain clamping rings.
- IV
Coping and edge
Parapets and edges get the membrane wrapped and new metal on top, so water can’t get behind it from above.
What we ask before we price it
- When did you first notice the problem, and has it changed since?
- Can we get into the attic, and is there a clear path to the access?
- Does the HOA need to approve materials or colors before work starts?
- Has anyone else inspected it, and what did they tell you?
- Is anyone in the house bothered by noise, dust or early starts?
How do I know my TPO roof is at the end of its life?
Shrinkage pulling at the walls, a chalky or cracked surface, exposed scrim and seams failing in more than one spot are the usual signs. One of those alone may be a repair. Several together usually mean the sheet is done.
Can you patch old TPO?
Often, yes, but aged TPO is harder to weld to and needs careful cleaning first. Once the sheet won’t take a reliable weld, patches start failing at their edges, and that’s when we stop recommending them.
Can TPO go over my gravel roof?
Not over the gravel. The stone comes off, and then the question is whether the layer under it is dry enough to stay. If it is and code allows it, a cover board goes down and the TPO goes over that.
Will switching from a dark roof to white TPO lower my cooling bills?
It usually reduces the heat coming through the roof, and in a Houston summer that’s a lot of heat. What you’d see on a bill depends on insulation, ceiling space and equipment, so we won’t promise you a number.
Do you replace the insulation too?
Wet insulation always comes out. Dry insulation can sometimes stay, and new boards can be added to bring the roof up to what’s required for the building. We’ll show you the core samples so you see what we saw.
Can the building stay open during replacement?
Usually. TPO welding is quiet work; tearing off gravel is the loud part, and we schedule that around the people inside. The commercial replacement page goes further into phasing an occupied building.
Who you are hiring
Google reviewers have given us 5.0 across 19 reviews, and the word that keeps coming up is honest. We would rather talk you out of a job than sell you one you do not need.
Military families and first responders take 10% off, and financing is available through Acorn Finance with a no-obligation prequalification. Ask about either when you call.
Leland Cannon spent 21 years in the Army and retired as a First Sergeant. Geoff Schardien served in Air Force Security Forces and has more than twenty years in residential construction. One of them walks every job before it starts, and you keep one phone number from the first visit to the last day.