If you are a roofing pro already installing TPO roofing membranes or considering starting to work with TPO there are some important installation intricacies that you need to be aware of to get your job done well.
TPO membranes are becoming increasingly popular both in residential and commercial single ply roofing markets across the US, offering an economical price as compared to its rival PVC roofing membranes.
TPO roofing membrane offers many benefits similar to PVC roofing, in the last couple of years, the membranes have been noted to age and deteriorate prematurely under conditions of high solar and heat loading.
This issue has been particularly prominent in the Southern states, that get both a lot of sun and heat year round.
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Why Proper TPO Membrane Installation Is So Important
While manufacturers are working on improving the membrane’s formulation to address this issue and revised ASTM standards for TPO are also in the works, manufacturers also believe that proper installation is key for a TPO membrane’s longevity and durability under these extreme conditions.
During MRCA’s 61st Annual Conference, a panel of representatives from various TPO manufacturers discussed TPO’s Long-term performance and offered important guidelines to roofing contractors on proper TPO installation techniques.
The TPO panel included representatives from GAF Materials Corp, Carlisle SynTec and other commercial roofing manufacturers.
The panelists made it a point that improper installation practices can go unnoticed during installation itself but can lead to major problems as severe as roof failures years down the line.
Top Tips For Proper Installation Of A TPO Roof
Hot-air welding of the seams was identified as the practice where most significant mistakes were being made by contractors.
They provided the following tips and guidelines for properly installing TPO membranes.
1. Test welds should be done at least twice daily — at the start of the day and after lunch. Also, it is really important to do test welds whenever the machine is restarted.
This is a necessary step that can prevent excessive heat during welding. Excessive heat has been identified as a major problem that needs to be safeguarded against because it can consume polymer stabilizers that will lead to the membrane’s deterioration.
Excess heat can result from the air temperature being too high as well as the welder speed being too low. Ideal welding temperature should be the lowest temperature that provides good seams at production speeds.
2. For proper installation, there should be no welder drag. A contractor needs to align the inside edge of the nozzle with the edge of the roller. If this is not done correctly, improper alignment of the hot-air nozzle can create gouges in the membrane outside of the seam.
3. It is important to be careful when probing seams, because incorrect probing or lack of care can also lead to problems down the line. When probing, it is best to use a blunt probe. Probes tend to sharpen with use and as a result must be occasionally dulled.
4. To avoid future problems, it is also critical not to crease the membrane when it is folded during installation.
Folding over the membrane can result in a hard crease and surface cracking. To avoid this, it is best to fold back the membrane for applying adhesives or fasteners. However, it is important not to place any weight on the fold to hold it in place.
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I just had a TPO roof installed on a roof deck. The installers took out the railing and the bolts holding the railing to the roof. They said we couldn’t attach a railing to the roof because it would cause leaks and they refused to put the bolts back in. Is this true? How can I put a railing around the roof? I looked into getting brackets to attach a railing to the side of the house but that is another $5000 which is insane for a roof deck we hardly use! For safety though, we definitely need something. Please help! What are my options???
I have a original 2005 commercial flat roof, the roof is SINGLE PLY ROOFING SYSTEM My question is, can I cover with TPO?
I’m the Buyers agent on a home with a partial TPO roof in Kansas. My roofer that inspected it for me said that TPO is mandated (I didn’t know if the heat welding was necessary) to be heat welded and the roof was not installed that way. The seller taped the TPO seams then coated it with Gaco. What would you recommend moving forward? It needs repairs and the seller is willing to do a Gaco re-coat and repairs with a 20 year Gaco warranty.
Great blog, appreciate all of the perspectives on single ply roofing. I’m a general contractor who has never installed TPO roofing, but I have a good customer who has a house design with a 1/4″ sloped flat roof which uses 8″ of type 2 EPS on the roof deck, before the TPO surface. They are not in a fire zone, so no requirement for Densdeck, plus there is huge shortage of that material in our local market. I’ve been told it could be 6 MONTHS for availability.
Anyway wondering if 1) could the TPO be installed directly over EPS insulation (concerned about the heat penetration of seam welding), or 2) could I use something like 1/4″ plywood as a coverboard? THANKS!
Can TPO be installed on a pitched roof.. like a 6/12? It will be on a warehouse over PBR panels using flute fill and 1″ ISO.
I just had it installed. I’m worried.
#1 glue down. And termination bar with tpo pulled into gutters with termination bar screwed right into gutters?. I have 45 yr old GUTTERS . If anything happens to gutters there go the tpo. Is this correct. No dripedge applied
Technically TPO can be done with termination bar, but screwing it into the gutter is definitely wrong. Also not using drip edge metal shows that your installer is cheap (insert expletive of choice here).
I hope you didn’t pay them full amount yet.
PS – glue down is not an issue.
I am a TPO installer. I am getting mixed answers so please share your thoughts. I have a customer with a 1300 square 4 ply tar and gravel roof over and old gypsum deck. Our plan is to vacuum off the loose gravel, install a 1″ ISO or maybe densdeck then TPO. Can this be mechanically fastened into Gyp and still recieve an NDL warranty?
Fyi..pull test scheduled for next week
Richard,
For NDL warranty questions you should definitely talk to your manufacturer.
They will give you the proper specs and tell you whether or not you can fasten into gypsum substrate.
Good luck, and let us know what the manufacturer says about this situation.
Perfect! Thank you for taking the time to share this. I am thinking about getting some TPO, and this really cleared up a lot of my doubts. Keep up the great work guys.
Best way to lift up ac u it’s to get single ply sheet under them without using a lift. Someone said you can use bottle Jack’s?
James,
Best way to lift roof-top AC and pretty much the only proper way, is with a CRANE. Renting a crane for 3 hours (with driver/operator) should cost no more than $150/hr (in many areas $100/hr) for 3 hours minimum. This exclude situations with skyscrapers and what-not or if you need police detail.
Bottle jack will make a hole in your roof – almost guaranteed.
Getting a crane is expensive, BUT … you will save so much in roof repairs – it’s actually cheap 🙂
Leo
Wonderful blog, thank you. I am building a new home in VA and my architect (who is in WA) has spec’d an 80 mil fully adhered TPO over tapered insulation with ballast on top for our flat roofs. There seems to be some debate about what should go in between the TPO and the ballast. My architect spec’d a 3 oz mat between the two. But local roofers are saying that this is not a good choice for the East Coast and we should use a breathable filter instead. My questions are: (1) What do you think of this overall assembly? Are there aspects where we could economize without reducing performance? We want to stay within requirements for GAF’s 30 year warranty. (2) What do you think of the debate on mat vs. breathable filter between the TPO and ballast? Thank you!
Asit
I think BALLASTED roof is stupid idea in the first place. You can do fully adhered over tapered insulation (make sure that Fiberglass Mat PolyISO is used).
If wind uplift is an issue (if you are near coast in hurricane zone), you can do fully adhered + mechanically fastened every 6-8″ with perementer half-sheet, or 2 rows of perimeter half-sheet. This will definitely get you the needed uplift rating and more. Consult with manufacturer if needed.
Ballast adds unnecessary weight, and is an issue if you need to repair. And it adds unnecessary cost.
I will not comment on the separation layer between ballast and TPO, as I already said – ballast is stupid. There are very few applications where ballast is really needed.
PS – consider PVC as an alternative to TPO.
Good luck, Leo
Thank you Leo. I appreciate your perspective and will look out for that insulation spec. The ballast is for aesthetic reasons because we can see the TPO roof from multiple locations on the upper floor. Given the ballast is here to stay, can you provide your perspective on choice of separation layer between ballast and TPO?
GAF specifies 3 oz Polymat, and if you use something else it may be a warranty issue.
Really anything can and will work as long as it’s not asphalt-based.
If you want to use breathable underlayment, there is GAF DeckArmor… It’s made for a completely different purpose but will do the job.
Another option – you can do a Gray or other color roof and not do ballast, or do Green Roof. Green roof will look a lot better than rocks.
I’m working on a historical brick building with parapet walls, installing a TPO roof. I’m tearing off 5 layers of old roll roofing, fixing any rot and then going to put down 1/2 inch insulation, covering parapet walls with plywood and then 60 mil TPO over all. My question is, if I am mechanically installing the TPO with no glue should I go ahead and glue the TPO to the plywood on the walls. Also, is 60 mil thick enough or should I use 80 mill?
Jason
You should adhere TPO to the plywood on parapets – use water-based adhesive – you can wet apply it, an put TPO right over wet glue (no need to wait). Don’t forget to terminate field membrane along the parapet wall.
As far as 60 vs 80 mil – if it is a warranty job, you should probably do 80 mil and charge more. If it is your own building – 60 mil is sufficient.
The most critical part with TPO is good seam welds. Thickness is secondary, because most TPO roofs have issues with seams.
Good luck
I’ve got a torchdown granulated roof system on the flat roof of my 11 year old row home. I’ve had repeated issues with the roof (cheap materials and other installation no-nos). I’ve decided to go TPO as I’ve read good things about this system and think it will provide the longevity that I’m looking for. I plan to install a roof deck on top (following recommended guidance).
Here’s my question: If the TPO is going to be an overlay on my existing roof do I need to lay a 1/2″ insulation/fiberboard down? I’m being told that it won’t matter and I don’t need to, but I’ve read some comments that a loose lay of TPO over a granulated roof membrane could do long term damage or create issues. I would love some guidance.
Jared,
You do need a separation layer! Not just fiber-board. If you will be placing a deck on top of your TPO roof, you also should install 1/2 DensDeck or something similar. DensDeck is super rigid board.
I recommend the following:
1) Tear off current roof – this is optional but I highly recommend this step. It will allow you to fix all the rotten wood beneath the roof.
2) Install 1/2″ fiberboard screwed into the roof, with roof screws and 3″ plates, and DensDeck adhered on top with 2-part adhesive.
3) Install 80-mil TPO roof, fully adhered (glued) to DensDeck. Do not use mechanical attachment, because if deck rafters are placed over screws, you will have a hole in the roof!
Do not use thiner TPO such as 45 or 60 mil. You need 80 mil under a floating deck.
What I suggest is the “more expensive approach”, but taking the deck apart to fix roof leaks, and then building it again will cost you $1000s. Doing it the way I suggest should result (assuming installation is good, and material won’t fail) in 20-30+ years of leak-free roof.
Lastly, do not hire roofers that tell you “it won’t matter and you don’t need to”. Their roof WILL leak.
Good luck
I’ve got a 1,700SF flat roof with granulated roofing. It’s 11 years old on a new home but not the best materials were used – been having issues at the edges. I’m having a new TPO roof installed and it will be an overlay. I don’t plan to rip off the existing.
Should I be laying 1/2″ insulation/fiber board first or does it make the most sense to just lay the TPO directly over? I can’t seem to find an answer on this. Any insight would be appreciated.
do you have any videos on setting a drain on a tpo roof with a deep sump
Hi Bob,
Maybe this video will help: https://www.youtube.com/watch?v=YPLOXK-RkJE
I’m not sure what you mean by “deep sump”, but if this video is not it, I will find and upload a video of me installing a retrofit metal drain on single ply roof.
Leo
I’m designing a residential flat roof over a porch area. The flat roof has concrete guardrails around the perimeter. Are there any recommendations for attaching the guardrails over the TPO roofing system?
Hi Daniel,
It would be helpful if you provided a picture or at least a drawing of these guardrails, so I could better assess the situation and provide recommendations. Typically some sort of square / round flashing is used to waterproof railing penetrations, but it’s best to see the elevation changes where these guardrails are.
You can upload picture to imgur.com and post a ling to the image in comments.
Cheers, Leo
Hello we’re getting a new TPO roof and the installer wants to scrape off the top layer of tar and gravel, put down EPS insulation and then the TPO. Is that normal or should they completely remove the tar and gravel roof?
Thank you!
Lee,
Honestly, both would be ok to do, as long as you don’t have rotten wood under tar. People often don’t even remove gravel – just put insulation over it, which is acceptable.
The real question he is – do you want to pay $1500-3000+ more just to remove the tar? Most people don’t want to spend the money. If it was my roof, and I knew there is no wood rot, I would not even scrape the stones. It really makes no difference, besides removing roof load.
Good luck.
Thank you! We will scrape the top layer as we’re going to have solar and would like to remove the roof load.
Roofers are finishing up, and the TPO goes over the top of the parapets and hangs down a bit. Stucco house, flat roof. I’m looking around at other TPO roofs in the neighborhood and don’t see this overhang. The roofer says it’s because our parapet walls aren’t very high, so they can’t attach it to the sides of the parapet, and this way it will seal the tops of the parapets. But if we have stucco work done they can stucco over the edges of the TPO so it won’t be seen from street level. Is that right? Stucco over TPO seems like something that wouldn’t work?
Lee,
You are coming from an aesthetically point of view, which I get… however, as a roofer, I will tell you that your contractor is doing the best thing for your roof and walls! If they did it the way you want, you will very soon have massive water damage and rot, behind your stucco, and just imagine the cost of fixing that!
You really want to have your roof go up and over the parapet. At the very least you want to have a parapet CAP (metal over the top of all parapets), which will look the same way.
Hiding roof edge behind stucco, will diver water behind stucco.
Good luck
Can you walk on a TPO roof? Can you put furniture on a TPO roof?
Frances,
You can walk on TPO to get something done or fixed, but not as a regular thing.
You cannot put furniture on TPO – it’s not made for that. It is strictly a waterproofing product.
There are options for you though – like IB DeckShield or DuraDeck (both PVC). These two are made for people to walk on, and put furniture on.
I’ve never worked with DuraDeck, so i have nothing to say about it. However I installed plenty of IB DeckShield, and it is an amazing product in installation, waterproofing, and durability.
Still you need to understand the limitations of these products: If you poke it with a knife or ice pick, you will puncture it.
Your patio furniture should not have sharp edges – feet must have plastic caps.
So if you want to be completely “careless”, it would be best to put an 80-mil PVC or TPO roof with a floating deck (wood or composite decking) on top. Then you can pretty much do whatever.
Cheers.
I have a new (End of 2017) GAF TPO roof on my new house. After first heavy rain, dark streaks of runoff from the roof appeared on the sides of my white stucco modern home. Streaks were also on the outside of gutters and over the drip edge. They will not come off. I have had the house pressure washed twice, once with water and detergent, second time with bleach. I have scrubbed what streaks I can reach with a wire brush and simple green. Nothing budges it it is not organic matter. I have talked with GAF, and the roofing company, the Sherwin Williams representative, and anyone who could be a source of info and help. Of course, the builder is not going to fix it (maybe after the lawsuit). And has come up with ridiculous excuses (like I live too close to an airport). Does not appear to be getting worse so it was the initial rain that did it help help or suggestions for additional info.
We have been advised to install TPO on our porch roof because there is little slope. My question is: Will house painters be able to walk on it without damaging it? We can’t do both roof and house painting at the same time, and structure must come before beauty.
Chris,
Painters need to be careful not to drop sharp objects on the roof.
Also no ladders on roof unless they use a piece of board / plywood under ladder.
TPO will be extremely slippery when wet…
Otherwise they can be on the roof no problem… Just use common sense.
A contractor put a TPO roof on a flat section of my house and installed a composite deck over it. On many places where the deck runners were thin, the areas went through the TPO. Is that common or is that going to give me problems in a year or two. It seems odd to me to punch holes in a perfectly good new roof. Thoughts please!!
Bob.
We had a TPO roof installed using a drip edge screwed into the eave. There was no additional flashing included to move water from the eave (no gutters). Is this a proper installation or should the flashing have been, at least, recommended?
David,
If you have wide overhangs (2.5-3′), you may not need gutters.
Were there gutters before you had your roof replaced?
The only flashing I can think of is the metal wrapping of the fascia board for “looks” and to prevent water damage. otherwise, on eaves, it’s either gutters or nothing.
Good morning TPO experts! Is it possible to use a steel drip edge over the TPO? The termination bars dont have a nice look to a residential installation. The drip edge would have to be affixed to the roof by puncturing through the TPO. Can a strip of TPO be welded or adhesive bonded on top of the screws holding the drip edge down to seal the top surface of the roof? This is the only issue holding me back from a TPO installation. Thanks very much for your help.
Flo,
Most common is to use Aluminum drip edge in exactly the manner you describe, but steel can also be used.
Most commercial projects don’t use termination bar. Same with residential, where aesthetics matter.
With TPO the only way is to GLUE a strip of TPO to cover screw holes. With PVC, there is steel drip edge with PVC cladding, so you can actually weld to it. There is no TPO clad edge metal that I know of. Welding is better, but gluing also works.
I hope this helps.
Thank you very much for the useful information. Just one more question … To my understanding, the TPO layer hangs over the side of the facia board and then the drip edge goes over the TPO layer. How much overhang should the TPO layer have over the side of the facia board? And how is the TPO layer attached to the side of the facia board? I know that screws will be used on the top of the roof to hold the drip edge on the top of the TPO layer, but I would also like to know how the TPO is attached to the side of the facia boards. Thanks again. Flo?
What is the cost per square foot for tpo in Albuquerque nm
Hi Lisa,
I have data for only one company that does TPO in NM – they are in Las Cruses.
They charge roughly $5.75 per sq. ft. with one layer rear-off, and basic insulation. A 1500 s.f. roof with them would be roughly $8700
Hope this helps
Can tpo roofing be used to re roof an RV camper.
Yes definitely. In fact, my 2005 RV has a factory TPO roof 🙂 some no-name company
It would actually be fairly simple to do – the only issues would be antennas / AC roof-top units. Other protrusions can be removed completely.
You plan to do it yourself, or hire someone?
Regardless of who will do it – use SolarSeal 900 sealant… not that garbage that’s sold in all RV/Camper stores/websites.
Hi I live in VA and have a flat residential roof of TPO installed in 2013. After our wind storm – tree falling on the house, we need to repair or replace the roof, mostly due to 10-12 puncture from the brances. These holes are 2 inches across or less. My roofer says that they will repair as many as four punctures but after that the integrity of the roof is at stake and we should replace the entire roof.
Also, if we replace are there any weather/temprature guidelines our roofer should be following regarding the installation (too hot, too cold)? Thanks
Kathryn,
Your roofer is trying to get an easy job out of you – this integrity thing is a bunch of “bull”. You can repair as many holes as you need / want, and it should not affect your roof performance or integrity… (assuming patches are welded in correctly, surface properly cleaned before patching, etc). Now one caveat – i don’t know what TPO you have, so 5 years on the roof, may have affected “weldability” … meaning patches may not weld well.
Now if your insurance would cover replacement (which I highly doubt, because it’s just punctures and they are easily repairable) … i would just take the money and still only do repair… it would really be a waste to trash a fairly new roof over few holes…
I would never work with this contractor though … because they are not honest with you. I don’t suppose your roof is still under labor warranty – so it doesn’t make a difference whether this or another roofer does the repair – as long as repair work is done well!
Good luck
Hi there. We have a newly framed flat roof deck over a garage (about 266ft and the slope runs 1/4 in every foot) and was considering TPO membrane to waterproof it. However, we want to put interlocking composite decking on top but underneath the decking we’re looking at appears to be hard plastic and not rubber. Wouldn’t that rip or cause tearing in the TPO membrane? And if doing so, would that void the warranty on the membrane? Also, what about water drainage under the decking? Is that recommended?
Mike,
To prevent tears, use a strips of material under decking. Since you have roof slope, I assume decking will run perpendicular to slope. Run membrane strips 12-16″ on center down the slope (perpendicular to decking). Something like this:
This will create separation between deck and roof, and provide space for water runoff. You may want to have at least 1/8″ thick strips – can double up your material.
As far as warranty, you need to clear this with manufacturer that you will use.
Good luck
I just got my independent contractors liscense and have been installing tpo and PVC rubber roofs and was searching the net for more information on these products as it seems not a lot of people are too familiar with them or know much about it,so any info is truly appreciated thankyou
Neil … “PVC rubber roofs”?? hmm 🙂
I recently had my roof done and I went from standard roof to a to type The contractor who installed it did not replace the rotted plywood nor did he use any type of insulation. When I asked them they stated that the manufacture did not require on this type of too installation. Is there any too roof that does not require on a flat roof. May I add that they laid it over existing 3/4plywood only
Alex,
You have to look at your particular product installation specs, but generally, TPO should not be laid directly over substrate. Some sort of separation is needed. Mainly because fasteners that hold down plywood, can back out and make wholes in the roof.
Now not changing rotted plywood is direct violation of ANY manufacturers’ installation specs, because substrate must always be solid and in good condition. I belive this also violates local building codes (consult with your building inspector).
Is your contractor licensed by manufacturer? If so, I believe, they should be canned from approved contractors list AND manufacturer should take care of your roof.
Who is the manufacture of your TPO membrane?
Good luck
Restore masters. Its goin on almost a year im having to deal with these guys. I wish they would. I have a good case againts them for not doing a proper installation and causing more damage to my home from all the roof leaks. also for not pulling permits. Then tried giving me a fake one. Not calling in an inspector saying that ot wasnt required. Then they sub out two more contractors to only fix the leaks. Yhat backfired on them when both contractors told them what a shitty job they had done and al the violations. Both contractors denied doing the work for restore masters. Then they gave me different installation guide lines from various tpo products which wasnt even the brand they used. I also got ahome inspector to submit a report , which stated all violations. It even got to the ceo of their company and he lied about making things right. I threatened them with a lawsuit. So they recently decided to refund my first payment and dont want to redo my roof or pay for all of the damages from their roof installation. I got all the proof in emails and the contractors and inspector willing to testify. Please help .
I really dont know who the manufacturer is. As i stated in my last response, they tried giving me three different installation guides from three different manufactures. They thought they could pull a fast one on me after I caught them in all their lies and unethical working practices. They should pay for their lack of good judgement.
I am Richard, I am doing a flat roof,I want to use a bitchathain under payment over OSB then put the TPO over that, thinking about the best installation I could provide, the customer counting costs does not want to use the butilain, I don’t agree do too integrity reasons, what do you as contractors?
Can you use TPO on a flat roof that is walked on daily?
Dan L,
No you cannot walk on it every day.
1st – you will void your warranty.
2nd – its very slippery when wet.
3rd – you will damage it very fast.
There are special walk threads made for TPO / PVC that weld / glue to the roof, and you can walk on them all the time.
Good luck
I have a very shallow pitch tar and gravel roof. One contractor is proposing to install 1″ to 1 1/2″ insulation on top of existing roof screwing it down with plates and then lay TPO membrane on top. Can TPO be installed this way?
Hi Mark,
Yes TPO can be installed that way. That insulation is referred to as ‘1/8″ tapered’ … I recommend 1/4″ tapered that would ab a 1.5″ to 1/2″ four by four feet board. I also don’t recommend installing it OVER existing roof, unless you know there are no leaks and substrate is dry.
Depending on roof size, your highest point (insulation thickness) can be few inches, because the 1″ to 1/2″ is just one section of 4×4′.
Good luck
Hi there, just wondering if you can tell me if it is common practice to place a second layer of TPO over the first, covering about 1000 square feet. Will this cause moisture or condensation between the layers with no where to go under it.
Brad, this is totally not standard, and should not be done. You are trapping moisture and creating tons of issues doing this.
Removing TPO is super easy (and thus INEXPENSIVE), and you can even reuse the insulation …. even the plates / seams can be left in place, to reduce removal labor… but main sheets need to be cut.
Good luck, Leo
Can house wrap be used as a slip-sheet?
John,
Yes, we’ve done it once, per request of the building owner – but I recommend dedicated slip sheet … it’s actually not any more expensive, and house wrap can act as a moisture barrier, and affect condensation under PVC membrane.
checking a roof for customer and ive been doing a few pvc roofs for a couple years now and i thought it was pvc but ended up being tpo the customer said antways i tried to weld a sample piece and would not adhere? are they not compatable products to weld together? iv e never used tpo and thats why im asking any help would be greatly appreciated
Hey Paul,
Quick answer – TPO and PVC are NOT compatible and will not weld together. It is strange because the welding process is the same, and you would think that since you melt two thermoplastics, when they are squeezed together they would bond. But no … they will not.
So my recommendation – either buy some scrap roll of TPO from a roofing supplier so you could weld patches, or find a local roofer that installs TPO and buy as scrap piece from them. I don’t think that you will need more than 50 square feet of membrane for patches and repairs. Might also buy some unreinforced patch material for corners, pipes, ets. Don’t uses field membrane for patching penetrations.
But … i should not teach you this – you’ve installed PVC before and know the process.
Best of luck – let me know how you made out.
Cheers, Leo.
I WOUD LIKE TO APPLY A FULLY ADHERED TPO OVER AN EPDM EXISTING ROOF.
THE INSULATION UNDER THE EPDM IS EXCELLENT AND I SEE NO REASON TO APPLY A 1/2″ ISO BOARD FOR THIS PROJECT.
IS IT POSSIBLE TO INSTALL IN THIS MANNER?
Art, you can do it, but ONLY if you remove epdm rubber roof first. You can then glue new TPO to the existing insulation.
You cannot glue TPO to EPDM.
Note – when you remove rubber, it may tear the parts of top fiberglass (or fiber) insulation, and there will be a lot of dust – so you should clean surface thoroughly before adhering the TPO membrane.
Optionally, you can slice the rubber (make many cuts to allow moisture to pass through) and then screw in 1/2″ OF FIBER INSULATION, and glue TPO on top. I know this is what you want to avoid – but it’s either removing EPDM completely or screwing in 1/2″ fiber.
3rd option is to slice rubber, install separation sheet, and Mechanically Attach TPO.
Best of luck – let me know how you did.
Leo
Do you have to use the adhesive to stick the new tpo to the insulation boards? I just looked at one that was not glued down. Looks a little waivy..
Matt,
You can use either adhesive or a mechanically attached assembly. Both are approved methods of installation. If you never see the roof, it does not matter much, which one you chose, unless there is some technical requirement for either method.
If you do see the roof a lot, then a fully adhered (glued) method is prefered as you most avoid imperfections.
A little wavy is normal in mechanically attached roof, as it’s virtually impossible to have a 1000 sq. ft. sheet to lay flat after you put 100s of screws and plates in it 🙂
I hope this answers your question
I have a single wide trailer with a 14×70 roof can I glue down a rubber
roof over the existing metal roof
Yes u can
Hello I have a roofing business in bowling green ky. Do you have any kind of literature to make giving estimates or proposals for installing a tpo roof system easier or coming up with square foot prices for material and labor . Perhaps you have guides for measuring, what to look for to figure out what tpo membrane is recommended and the flashing and accessories needed. Last thing and I apologize for all the request but can you send or email price lists for tpo membrane and accessories
Brandon,
You need to partner with a manufacturer and they will provide most if not all the information you are looking for.
Contact a salesman for the MFG of your choice and see if you can become approved contractor
Nice blog post! I am a roofer (it may sound strange) and I like the fact that people are giving so useful advises.