Q: I have received proposals for re-roof of my house however each proposal calls for different underlayments with significant price differences. I live in Southeast Florida. I would appreciate guidance as to what makes the most sense. Thank you for your input; it is greatly appreciated!
– Install on Roof Deck Area: 2.1 One layer of 30# ASTM D-226 asphalt saturated organic felt tin capped to sheathing; New 26 galvanized 2×2 drip edge, vent and valley metal flashing; and new roof vents (GNV);
-One layer of 90# ASTM D249 mineral surface tile underlayment set in a mopping of ASTM D312 Type IV hot asphalt; NO PEEL N STICK!
-Standard color cement tile with ICP AH-160 PolyPro foam adhesive; NO NAIL PENETRATIONS!
– Install on Flat Roof Area: One layer of 75# asphalt saturated base sheet tin capped to sheathing; One layer of fiberglass sheet set in hot asphalt (ASTM D312 Type IV); One layer of CertainTeed GMS modified bitumen (white mineral surface) set in hot asphalt (ASTM D312 Type IV);
Option: add’l $4,500 – GMS Modified: Superior tile underlayment
2nd option: add’l $3,100: Seam Tape: Secondary Water Barrier (SWB)
Proposal 2: (cost is about $8,000 more than proposal 1):
– Install 1-#30 ASTM Roof Membrane mechanically fastened
– Install one layer of self-adhering modified bitumen membrane tile underlayment.
– Install cement color thru roofing tile, (roll style, standards colors) using 2-part polyfoam adhesive
– Flat deck roof area shall receive 1 #75 ASTM extra thick base sheet membrane mechanically fastened
Proposal 3: (cost is $12,000 more than Proposal 1):
– Dry in all roof areas with 30# ASTM base sheet.
– Install standard GALVANIZED 2×2 eave drip, valley, and Inspect & Re-Use Existing wall flashings.
– Install Self Adhering Tile Underlayment to all pitch roof areas and 2 layers in valleys for UV exposure via weave installation.
– FLAT ROOFS/WOOD DECK: Install self adhered 3-Ply Modified Bitumen System
– All field roof tiles fastened with ICP FOAM ADHESIVE and hip/ridge caps fastened with approved adhesive
A: The Florida State Building Code, and the added requirements in Miami-Dade and Broward Counties, are about the toughest in the US when it comes to roofing. Also they have changed the code a couple of times in recent years, getting much tougher in 2002 after Hurricane Andrew, and then revised further in 2007. Florida codes are most stringent in areas subject hurricane-forced winds and flying debris, so-called High Velocity Hurricane Zones.
To meet the current code, roofs must use an approved underlayment system, which Florida calls a Secondary Water Barrier or Secondary Water Resistant (SWR) barrier.
However, not all code-approved systems meet the requirements of the insurance industry, under the guidelines of the Florida Office of Insurance Regulation. To qualify for an SWR discount on your homeowner’s insurance, you must use either a peel-and-stick membrane bonded directly to the roof sheathing (option A below), or a special type of closed-cell foam sprayed to the underside of the sheathing. Also, you must have good documentation, such as a signed contract, that you used an approved system. Installation photos are also a good idea since most of the work is hidden.
The goal in all this is to create a waterproof layer that seals around nails and will stay in place if high winds blow off a section of the roof covering. An intact underlayment keeps water out of the house and helps prevent penetration of the roof structure. Once the structure is penetrated, catastrophic wind damage often follows. The main underlayment options listed in the code are:
A) an approved peel-and-stick membrane adhered directly to the roof sheathing
B) an approved peel-and-stick membrane adhered to roofing felt, mechanically fastened to the roof sheathing
C) minimum 4-inch wide peel-and-stick tape over all seams in the roof sheathing, covered by an approved underlayment (ASTM #30 felt or an approved synthetic)
D) a mechanically fastened base sheet covered with a hot-mop cap sheet.
All of these make sense to me except for Option B. To get the full benefit of peel-and-stick membrane, it needs to be bonded directly to the roof deck. The only benefit of placing it over a layer of felt is that it is easier to remove 20-30 years later when reroofing. Also, Option C is suspect unless you are using a weatherproof sheathing such as the Zip System.
All of your proposals meet the building code, but not all meet the requirements of the insurance industry. In particular, Proposal #2 seems to place the peel-and-stick membrane above the base sheet.
It sounds like your roof contains both flat and sloped sections, which are handled differently in these quotes. There are a lot of moving parts here, so apples-to-apples comparisons are difficult. Also, there are dozens, if not hundreds, of underlayment systems on the market now and many use proprietary materials. Most synthetic and modified-bitumen (rubberized asphalt) products do not have national standards, adding to the difficulty in comparing products.
Two of your proposals fasten the tiles with foam adhesive. In general, two-part foam adhesives, like the one proposed, provide better hold-down strength than nails or screws. It also eliminates nail holes in the underlayment and provides a cushion that helps prevent tile breakage from walking on the roof. One-part foams are sometimes combined with nails or screws for a hybrid approach with similar performance at less cost.
So let’s break it down:
Proposal 1 is a hot-mop system with all new flashings and two-part foam tile attachment. Hot mop underlayment is the traditional approach in Florida. This uses a mineral-surface cap sheet, which adds to the durability. If done well, these systems are durable and easy to repair if a leak forms. However, a high-quality peel-and-stick underlayment that is rated for high temperatures will probably outlast hot mop. The option for a white mineral surface on the flat portion might increase its longevity (compared to standard hot mop) and should reduce your cooling load somewhat. Adding seam tape is a belt-and-suspenders approach. However, if water has reached the wood sheathing layer, I don’t think the tape will provide much benefit as you can expect delamination or decay in the wood and failure of the tape. Also, peel-and-stick in the valleys would be a worthwhile addition to this approach.
Proposal 2 places the peel-and-stick membrane over the base sheet. I’m not a big fan of this approach, and neither is the Florida insurance industry as far as I know. Also, it’s not clear what the top layer (cap sheet) is on the flat area. Standard peel-and-stick is not a roofing surface as it will degrade under long-term exposure to UV.
Proposal 3 uses self-adhered underlayment (good), double layers in the valleys (very good) and a 3-ply self-adhered system of the flat areas. With peel-and-stick systems, it’s best to go with a proven product such as Grace Ice & Water Shield or Certainteed WinterGuard, preferable the high-temperature (HT) version. Also make sure the deck surface is clean and dry (and primed if the roof deck is OSB).
The flat area uses one of many newer systems competing for the flat roof market. I’m not sure exactly what this is, but would want more information on the system, manufacturer, guarantee, and track record. How long has it been on the market and how many roofs has the contractor installed? What does he like about the system? Any downsides? Also, this proposal wants to re-use wall flashings. Unless they are in excellent condition, this is risky. However, they can be expensive to replace in a stucco wall.
For my money, the best material for flat and low-slope roofs is EPDM. Done properly, it will far outlast any other material – typically 40 years or longer. PVC has similar characteristics but is less commonly used on residential projects.
Finally, with any roofing product and system, the installation is at least as important as the materials. So choose an experienced contractor with a sterling reputation, a long track record in the area, and a strong written warranty. For the most part, you won’t see the little details that make the difference between a 10-year and 20+ year roof.
– Steve Bliss, BuildingAdvisor.com
Theodore Grossman says
Peel-and-Stick vs. Synthetic Underlayment for Tile Roof?
Thank you for your roof underlayment details. I live in So. Florida (hurricanes, rain, heat & humidity). My 22 yr. old cement tile roof leaked in the valley after heavy rain & I want to do a re-roof.
1) What do I do with the existing solar-powered roof turbine?
2) What is the recommended underlayment for cement tile?
Peel & stick is recommended by half the roofers I’ve interviewed. Is Titanium UDL 30 a good choice?
3) Any other material or installation procedures I should be aware of?
In answer to your questions:
1) Depending on how the turbine is installed, they will either re-flash it in place or remove it and reinstall. Energy experts generally have mixed views on these fans. If the ceiling plane is not well sealed, then the fan will be pulling conditioned air from the house into the attic. This cools the attic, but will increase your cooling bill. The money would be better spent building a tight ceiling air-barrier and adding more ceiling insulation if needed.
2) There are many options for roof underlayment. A high-temperature peel-and-stick membrane is a good option. This will seal at every nail and screw penetration and can survive a blow-off better than mechanically fastened membranes. Choose a well-established product, as the newer ones have not had time to establish a track record. The biggest downside is that self-adhesive underlayments are difficult or impossible to remove when re-roofing. The choices are to leave them in place or replace the sheathing – a costly option. Titanium UDL is one of the better synthetic underlayments on the market. It has all the right approvals and contractors like it for it’s ease of installation and no-slip walking surface. On a tile roof, I would go with the heaviest option UDL 50.
3) Carefully follow manufacturer’s instructions with any roofing product or you risk performance problems and an invalid warranty. With any product, the installation is as important as the material used. For example, Titanium 30 should be installed with cap nails only, while cap staples are allowed with UDL 30. Peel-and-stick must be carefully applied to a clean deck and rolled with a heavy-duty hand roller as specified by the manufacturer (some call for a heavy, weighted roller). With cement tiles pay attention to the ridges, hips, and roof edges, which are the most common failure points in heavy winds.
Also, play special attention to flashings – the most like sources of leakage. Make sure you choose a material that will last as long as the tiles. Above all else, choose a roofer with a lot of experience and a stellar reputation, even if you have to pay a litter extra.
Read more on Tile Roofing Underlayments
Hot mop vs. Peel & Stick for Reroof in Hurricane Season
Still haven’t decided if hot mop or peel-and-stick is way to go, but either way I am concerned about having my tiles removed, then the new underlayment exposed over the hurricane season.
Currently there are a couple small leaks.
Any suggestions are helpful. In the meanwhile I have cleaned under the tiles, added tar sealant, then reapplied the tiles with tarps over those – so that helps but is just a BandAid.
You really don’t want any underlayment exposed during hurricane season. Make sure the new tile is delivered or ready for delivery before they tear off the existing roof. Get assurances from the contractor that the roof deck or underlayment will not be exposed for longer than necessary. Peel-and-stick is certainly a faster installation than hot mop, so there is less chance of exposure to bad weather.
In the event that the underlayment is exposed to stormy weather either during installation or due to a blow off, a properly installed, high-quality peel-and-stick might perform better than a typical hot-mop, but there is not a lot of data on this. Some peel-and-stick manufacturers claim that their products can withstand hurricane-force winds as long as all details are followed. For example, many require priming of OSB sheathing, which is not always done. Also, they specify a clean, dry, smooth surface — not always the case on a reroof.
Also, all peel-and-stick membranes are not alike. The industry leaders are Grace (now GCP), which invented the product, and Certainteed. Both make a high-temperature version, suitable for hot climates: Grace Ice & Water Shield HT and Winterguard HT. Some of the newer peel-and-stick products do not bond as well or seal as well around penetrations according to reports from the field.
Underlayment exposure limits vary for different materials. Exposure limits for hot mop vary with the specific installation method and type of cap sheet and can be difficult to predict. Published exposure limits for peel-and-stick vary from 30 days to 6 months or more. However, all underlayments degrade from UV exposure and their ultimate longevity can be compromised, so the sooner it is covered up the better.
HAL Krantz says
What Are Single-Ply Membranes?
What does EDMP stand for and what other membranes can be used on residential roofs?
Is Silicone Coating Good For Hot Climate Roof?
I am in the process of insulating above my flat roof and I wanted to see if I can get some insight into the best way to do so. Currently, our roof is 7 years old and in great condition. However, the flat roof side of the house, approximately 350 sq feet can get extremely hot because on the inside of the house it’s an exposed beam and on the outside on the roof just membrane. We have gotten different estimates on how to insulate above the flat roof to keep that side cooler and I have provided them below:
1) Silicone coating
2) Foam insulation boards w/ silicone coating
3) Foam insulation boards w/ Hot mop
Obviously, I’m not in the roofing business and just want to obtain the BEST method on how to cool this area of the house and something that will last a very long time.
Can you please advise the best way to insulate above the flat roof?
Silicone roof coatings are bright white, making them a good choice for energy savings in hot climates.
Studies conducted by the Florida Solar Energy Center (FSEC) have found that bright white roofing can substantially cut cooling bills and comfort. In one study of Florida homes, the average savings with white roofing was 20%. Most of these homes used tile or shingle roofs. Not surprisingly, the greatest savings were in homes with uninsulated roofs.
The savings will probably be higher for a flat roof with black hot-mop. For example, in another FSEC study of commercial buildings, savings ranged from 18% to 48% , with an average savings of 25%.
How much extra will you save by adding a layer of foam insulation boards? It is difficult to say because there are many variables and savings can vary a great deal from one home to the next. In new homes, FSEC recommends R-30 roof/attic insulation, but that is not an option for you.
However, since you get the greatest benefit from the first few inches of insulation, it’s a safe bet that adding one or two inches of roof insulation will be a good investment – and now is your only chance to do so. Most foam board is around R-5 per inch of thickness.
Adding insulation follows the “Law of Diminishing Returns.” Each time you double the thickness of insulation, the additional savings are reduced by half. For example, if you save $200/year on your heating/cooling bill with R-5 insulation, you will save $100 more with R-10, $50 with R-20, and a mere $25 with R-40. The optimal amount of insulation balances the cost of the insulation with the savings over a reasonable number of years.
As for what finish roofing material to use, there are many options. Hot-mop and modified bitumen are still widely used in Florida. Up north, the best choice for residential flat roofs is EPDM or other single-ply membranes. All flat roofing systems require knowledge and skill, and some maintenance, for a long-lasting installation. Having sufficient slope to avoid ponding of water is important. The devil is in the details.
Silicone roof coatings are used mainly in commercial buildings to restore old hot-mop roofs and as a protective coating over spray-foam roofing. Silicone roof coatings have an average life-span of 10 to 15 years, but can usually be recoated at that time. I am not familiar with using silicone over foam board. One concern with foam board insulation is shrinkage and expansion putting stress on the roofing membrane.
Whatever product you choose, ask about the longevity, maintenance requirements, and a written warranty. Roofing warranties are usually pro-rated over time and often for materials-only, so they aren’t very valuable. But they do provide some indication of the contractor’s confidence in the product. Also ask how long they have been in business, how long they have used this specific product, and whether they can provide references.
Foam Adhesive vs. Screws for Roof Tiles?
I am getting two bids for a new tile roof. in Florida. One uses a two-part foam adhesive and one uses mechanical fastening of the tiles. Which is better for longevity, storm protection, and leakage? Thanks
In product testing, two-part foam adhesives provided better hold-down protection in high winds than mechanical fastening with nails or screws. So, assuming that the foam is installed properly, it should provide the best protection in storms. Another benefit of foam adhesive is that the foam cushion reduces cracking from walking on the roof and other loads (like a fallen branch). A third benefit is no penetration of the underlayment, except along the bottom course where some codes require mechanical fastening even with the foam. The edge of the roof is exposed the the greatest uplift forces in high winds.
The main downside is cost and some roofers are concerned that removal of tiles for repair or replacement will be considerably harder.
A less expensive middle ground is to use one-part foam along with nails or screws. This provides similar hold-down performance to two-part foam. If you pair this with a self-sealing underlayment (such as peel-and-stick) then you won’t need to be concerned about puncturing the underlayment.
Your local code will determine the minimum fastening strength required, but you may choose the build above the minimum given the increasing strength of storms in many areaa.
Hot Mop Best Option For South Florida Roof Underlayment
The hot mop is still the best installation practice for homes in southeast Florida (statewide in my opinion).
Speaking specifically about projects in South Florida (Palm Beach, Broward, and Miami- Dade counties):
As mentioned this area of Florida has the most stringent building codes in the nation when it comes to roofing. When engineering a roof system you want to make sure that ALL parts of the roof have a product approval with PUBLISHED data. We can quantify the data with a hot mop system, you can look up and find the testing results with published numbers pertaining to each layer ( 30# ASTM-D226, ASTM-D312 asphalt, ASTM- D249 mineral surface underlayment) but with peel & stick (or self-adhered) systems they do not provide uplift data. They just say its code approved. As a roofer in the area, it’s hard to understand why someone (homeowner or contractor) would use a product they can not quantify their claims instead of taking the word for it, but I digress.
Another issue we are having with peel & stick is its severe lack of UV ray stability. Tile manufacturing supply is lagging behind and causing long lead times. If you have a home dried in and peel and stick in place the south Florida sun wreaks havoc on it and degrades it prematurely. the majority of the MANUFACTURERS requirements and guidelines say the peel & stick needs to be covered within 30-90 days. Unfortunately, in some cases, tiles are taking longer than that to be delivered, again not good for the underlayment to degrade before you even get the tiles on. Some manufacturers say they’re good for 180 days left exposed, but again it comes with an asterisk. I’ve seen jobs down here that have had the peel & stick exposed for too long and it started to discolor and bubble in areas – why install tile on an already comprised underlayment system?
On the point of UV limitations, people are offering additional peel & stick in the valleys. This seems good on paper but why would you use a material with such a short life span in the UV environment in an area that will almost always have some degree of sunlight coming through.
Peel & stick directly to deck does stay ‘stuck’ to the roof sheathing. but, as mentioned before, it makes it almost impossible to get off the deck for repairs or reroofs. These peel & stick products have not been lasting near as long as they claim in our area and have been needing premature reroofs. By not being able to get the underlayment off to inspect the deck – it could become a larger financial burden for the homeowner in wood that would need to be replaced or wood that does need to replace may be overlooked because the deck cannot be inspected properly.
The building authorities in south Florida are becoming aware of issues that originate from using peel & stick in direct to deck applications and changing their guidelines accordingly. For instance – Broward & Miami-Dade counties do NOT allow peel & stick directly to the deck. It has to be installed on top of a mechanically fastened anchor sheet. Palm Beach County still allows it but some municipalities are changing their guidelines to help their residents. For instance in Boca Raton and Delray Beach have already implemented changes to their guidelines and now peel & stick is NOT allowed to be direct to deck, again there has to be a mechanically fastened anchor-sheet. The problem with this system is peel & stick installed OVER a 30# anchor-sheet does NOT stick to the 30# anchor-sheet. It adheres to the tin-tags (nails used to fasten the anchor sheet) so you are not getting a completely fused membrane. My team did a reroof on a home (well before the roofs ‘expected’ life cycle) that had a peel & stick over a 30# and my guys were literally pulling the underlayment off the anchor-sheet with their hands, not good.
I want to be clear that I am not against innovations in the industry, I welcome it. However, I do feel it is our job to service the community and provide the best options available and not cut corners. Putting it simply I would not use the peel & stick on my personal home.
Peel-and-stick has been used a lot longer and has a much better reputation in New England where I live. Instead of using it at eaves, valleys, skylights, and transitions, more contractors are just putting in on the whole roof, especially on additions.
It is rarely exposed to UV for more than 30 days and has established a good track record. Clearly it should not be exposed to UV longer than recommended by the manufacturer.
Also, in South Florida, high-temperature peel-and-stick would be a better choice than the standard material. High-temperature membrane is also recommended under metal roofs in any part of the US due to the high temperatures that can build up.
As with any building technique installation is as important as the material. Of course, if you put peel-and-stick on wet, dirty sheathing, it’s not going to work very well. Like everything else in construction, the installation is as important as the materials.
Hot-mop roofs are also subject to premature failure if the workmanship is poor or the wrong materials used. I think the jury is still out on which is the more reliable and long lasting, and which can better weather a severe storm.
What do you tell customers about the longevity of hot-mop underlayment in South Florida? Also, what specs do your recommend for materials and installation?
I do hear that a lot about peel-and-stick being used up North. A lot of my customers are snowbirds who split their time between both areas.
Now I, totally, agree with you about installation practices playing large roll in a project but at the end of the day if the material can’t with stand the environment it severely weakens even the best installation practices. That’s what we’ve seen in direct to deck applications, premature material failure.
Longevity of the roof is a loaded question, for all systems. It ultimately comes down to how the roof is cared for. Our roofs, as all, take a beating over the years from the elements. Here can be especially aggressive because there’s no real ‘down time’ for our weathers. The sun down here literally bleaches rocks, excessive amounts of heat retained in the building itself, the wind borne debris, wind blown rains, etc. Then we have homeowner factors, have they cared for the roof? Are their gutters clogged and overflowing back to the eave/soffit? Have they cleaned it? A lot of people (and community associations mandate) roof pressure cleanings. We’ve seen some of these companies use caustic chemicals to remove mold and mildew from tiles, which it does but it also is terrible for the underlayment – shingle, tile and metal are at risk. I’ve seen companies use too high pressure and cut through underlayment. What I am getting at is there are a lot of variables at play.
If a homeowner is somewhat cognizant about caring for the roof a properly installed 2 ply hot-mop system will last 20-25 years. My business actually were the original roofer for a lot of the surrounding communities (early — mid 90s) and in applications where the builder requested the 2 ply hot mop application are still well intact and performing well.
Now some did not last that long, but the majority of the issues arise from the roof being mechanically fastened (a whole different conversation about attachments) or a specific builder spec-ing an alternative underlayment system to reduce their overhead and maximize their profit.
Our code drives what materials may be used, most are using the same. So my 30# anchor sheet is gonna be the same as the next, same with the asphalt, cap sheet and tin tags. The biggest difference in this respect is going to be tin tag patterns and meeting or surpassing code. For instance my standard nail pattern adds 50% more fasteners than the code minimum required. We do this because of our own personal philosophy.
Zach – based upon your comments, it would appear you favor Proposal 1 listed above. If so, would you suggest proceding as proposed or consider any of the options as well. My concern is to have a good product and no problems. The company in this proposal is well respected and has been in business a long time. While I want a good product that will last 20 years and be a positive factor in any potential resale. I am not concerned with one that will last 30 years or so as promised by peel and stick. I’d appreciate your opinion. Thank you
Should Peel-And-Stick Underlayment Apply Direct to Sheathing?
I need to replace my tile roof which is 25 years old. I live in Palm Beach County.
My Roofing contractors offers two methods which pass County Code:
1. Direct attachment Peel & Stick” to the plywood then use 2 foam process to attach the concrete roof tiles. 2. Install 30 Roofing Paper mechanically attached to the plywood, then Peel and Stick, then 2 foam process to attach the concrete roofing tile.
Which method is better, long lasting and safer for hurricanes in Florida? Why one is better than the other?
Appreciate the help
Peel-and-stick was developed to seal to wood, OSB, and other structural materials to seal out water. The original product was Grace Ice & Water Shield, used to protect the eaves from ice dams in cold climates. It has a very aggressive adhesive that will bond permanently to the roof sheathing as long as it is installed correctly to a clean and dry surface. Contractors replacing 20-year-old roofs are finding the product intact and in good condition. The only downside is that it is difficult or impossible to remove when it is time to reroof.
It doesn’t make a lot of sense to me to apply the peel-and-stick over a layer of roofing felt that is mechanically attached to the deck. The weak link here is the mechanical attachment of the felt with nails and plastic or metal caps. If a section of tiles blows off in a hurricane, the peel-and-stick directly bonded to the structural deck will have a better chance of staying in place than the mechanically fastened felt.
In both scenarios, you get the benefit of the peel-and-stick self-sealing around nails, although with foam adhesive, there will be few holes in the underlayment. Some codes require screws in the first row of tiles where wind uplift is greatest.
Two-part foam adhesive is a good product as long as it is installed correctly to an underlayment approved by the foam manufacturer. In tests, it performs better than screws for resisting wind uplift. It also provides a cushion effect which helps reduce cracking of the tiles. As with any technique, proper workmanship is essential for good performance.
Not everyone is a fan of foam however. Stainless-steel screws will outlast you and me. The service life of urethane foam adhesive is less easy to predict. If it were my roof, I would contact the foam manufacturer for data on the foam’s lifespan and warranty information.
Best of luck with your new roof!
Thank you so much for your very detailed response. It is confusing but at least now I have an understandable basis to ask some questions and understand responses. All of the companies that provided quotes are well know reliable roofers who have been in business for a long time.
I have one more quote due next Wednesday and I should hopefully be able to figure this out.
It is very confusing as there are so many options now, a lot of opinions, and few facts about the real-world performance of many of the newer products and systems. Certain products are good for the contractor in that they are easy to install and/or profitable, but may not be optimal for the customer. Also the quality of some materials, such as organic felt paper, has changed over time – and usually not for the better. A lot of things look great when installed, but may not look so good in 20+ years.
Hot mop has been around for many decades. There are different flavors of bitumen with different melting points and degree of odor and fumes. Also the type and number of plies, attachment to the deck, and the top “wear surface” can vary a lot. On a flat roof, the top layer should should have gravel, a mineral-surfaced cap sheet, or a reflective aluminum coating. The average lifespan for a 3-ply hot-mop roof in Florida 15 years. A 2-ply hot-mop underlayment, protected from sunlight, might last longer. Good workmanship, especially around flashings, is critical for a long service life. Also, more plies usually translates into longer life.
Peel-and-stick membranes have been used in roofing for over 30 years. The first product was Grace Ice & Water Shield, used along the eaves in cold climates to protect against ice dams. The product has established a good track record and usually outlasts the roofing shingles, at least with asphalt. Peel-and-stick is now widely used in valleys, and around flashings, penetrations, and other roofing trouble spots. In cold climates, more roofers are using this product on the entire roof as an extra precaution against leakage. Peel-and-Stick also protects the building from water damage during construction. This is especially important on reroofing, renovations, and additions, although the membrane shouldn’t be exposed to sunlight for more than 30 days, unless rated for longer exposure times.
Again, best of luck!
Powell Castro says
Thank you for all the great information. I am also getting a re-roof in South Florida and was wondering how to identify a high-quality peel-and-stick underlayment? All the quotes I received include the installation of a 30lb. ASTM base sheet and then a peel and stick on top. The roofer I’m probably going with is using the following peel and stick but I don’t know if it is any good. It’s Boral (now Westlake) TileSeal HT.
How do I identify a high quality peel and stick or is there some independent ranking of peel and stick underlayment I can reference?
The first peel-and-stick roofing membrane, introduced over 30 years ago, was Grace Ice & Water Shield (now owned by GCP Applied Technologies).
There are now dozens of similar products on the market, which vary somewhat in composition, thickness, surface film, and other characteristics. Without being a chemist, it’s difficult to meaningfully compare one product to another.
However, there are indications that a product is manufactured to high standards and will perform well: compliance with ASTM standards, acceptance by the national ICC building code, and (in Florida) acceptance by Florida state code and Miami-Dade County. Code “acceptance” is achieved by submitting relevant test results to building code officials who determine that the specific product complies with the intent of the code.
Boral TileSeal HT, the product you refer to, has all these approvals. Also, Boral (now owned by Westlake) is a well-established manufacturer of roofing, siding, and other building products, with a good reputation in the field. They support this particular product with a 30-year warranty. While building product warranties need to be taken with a large grain of salt, this is at least a vote of confidence in the durability of their product.
Based on this, I would feel comfortable using this product on my own house. Of course, the installation is always as important as a product and, if there is a problem, a reputable contractor is critical in getting warranty support from the manufacturer. So it always pays to choose a contractor carefully.