Author Archive for Ann – Page 2

Cell tower equipment:

More building owners are renting their rooftops to wireless cellular companies. These should be shut off during roofing as repeated exposure to these signals in the concentrations that occur next to the equipment is dangerous for the roofers. Contact the cell companies in advance to find out the details for turning these things off during roofing.

Previous steps:

If you are at this point you have hopefully read through our recommendations on how to check out your existing roof and prepare it to receive a new roof and checked out the 10+ year section. Instead of repeating the 10+ year section this section builds upon it. What extra things are required to get a 20 to 30 year roof? The combination of design, materials, workmanship and timely maintenance makes just about anything last longer. This is especially true for roofing. If any of these items is poor the roof is likely to fail before 10 years. If all of these items are good we would expect any roofing system installed today to last for 20 years. After being so generic, what follows will attempt to be specific on how to obtain the best design, materials and workmanship. It will also touch on some different roofing systems and the details manufacturers require to get their longer warranties.


The 10+ year system discussed many design issues that need to be considered when re-roofing and should be addressed by anyone who wants to propose a new roof on your property. There are four different categories of people that can design your re-roofing solution: architects, roofing consultants, roofing contractors and roofing material manufacturers. All of these people will have different opinions on what should happen. One could reasonably expect architects, roof consultants and roof manufacturers to overdesign the roof in order to protect themselves or potentially make more money. One could expect a roofing company to overdesign (to make more money) or underdesign (to get the work from a competitor). Make sure the design issues in the 10+ year section are addressed with satisfactory answers. If you can’t get satisfactory answers find someone else to work with. Make sure to ask for options. Make sure more than one roofing manufacturer is specified or the prices will be higher. How do you start? It’s almost as tough as picking a mattress.

  • Option 1 – look for a consultant. In our experience architects are not as experienced with roofs as consultants. Consultants are solely focused on roofs while architects focus on many different aspects of building. The consultant can help select the roofing contractors and manufacturers. In theory the consultant will be the most objective. Use the yellow pages, internet, roofing systems manufacturers, roofing materials distributers, building associations and roofing contractors for recommendations.
  • Option 2 – pick a handful of contractors and solicit bids. Narrow the designs bid to one or two and get them priced apples to apples by other contractors. In many cases this will encourage the other contractors to highlight any weaknesses in the design. Use the yellow pages, internet, roofing systems manufacturers (check their web sites for award winners), roofing materials distributers, building associations and roofing consultants for recommendations.
  • Option 3 – contact a few manufacturers and ask them to specify something and recommend contractors. Using the manufacturer to specify a design usually results in a good solution however that solution will lock you into that manufacturer’s products. If one manufacturer’s products are specified there is no incentive for that manufacturer to provide the best prices on their materials – so you may want to ask two manufacturers. Also be careful of over design – it’s your money they are putting into their pocket. The major manufacturer’s we see in New England are Firestone, Carlisle, Versico, Mansville, Sika-Sarnafil, Duro-last, Dow/Stevens, Genflex and GAF.


If you have a building of any size it would be worth obtaining a manufacturer’s warranty for many reasons (previously specified). In the previous section we listed a number of manufacturers that have all been around for a few decades. There are other manufacturers. Check them out carefully as you would any other company you expect to do long term business with. Do their products have a track record? What is the size of the company? Does it have reserves specifically set aside for warranty payments – if so how much? Confirm they will send an inspector out to look at the finished roof. The web sites of manufacturers have a wealth of information as to what their products are and what the different warranties are. Watch out for new products without a proper track record. Lab testing does not equate to what a product experiences in the field – there are just too many variables to account for.


There are generally 3 parts to making sure superior workmanship is done. First is to get an experienced roofing company with experienced installers. Second is to have a knowledgeable independent party check the work as it is happening. Third is to have an independent party check the work after it is finished. Doing the due diligence on the roofer will mostly result in the first and obtaining a manufacturer’s warranty will take care of the third. Finding an independent party to check the work as it is happening is more costly and rarely happens.

How can you tell whether a contractor does quality work that will last decades is a tough question. All of the usual investigative methods will apply – how long in business, referrals, what have you done similar to our project, etc.. Some additional thoughts – roofing materials manufacturers license contractors to install their products. Manufacturers will only warranty roofs installed by their licensed contractors. As time goes on manufacturers keep track of calls made against those warranties. Some manufacturers measure that quality and quantify with awards. Usually the awards are only publicized if the contractor puts on a certain amount of their product. So a call directly to the manufacturer of choice can yield some interesting referrals, especially if you ask the correct questions – like who has the best experience in the last 5 years / 10 years that is within 50 miles of my property? How many installations would that encompass? Coming at it from the other direction would be to find out what manufacturer a contractor is quoting, then call up that manufacturer for their recorded experience with that contractor. If you can skip any local manufacturer’s representatives and go straight to the main offices you might even get a more data driven answer as opposed to someone’s judgement (which may also be useful).

Another item to check is the experience modification rating which can point towards the safety experience of the company. A number of 1 or below is good. In Massachusetts you can find that number on-line ( Other states may also provide this – the contractor should also be able to provide this on his insurance agent’s letterhead.


Maintenance has been discussed before. If you do not limit access to the roof, at least protect it as much as possible, periodically inspect and repair damage, the roof will fail early. The better job you do the longer into the 2nd or 3rd decade the roof will last, especially as the roofing systems materials and installation methods improve.

Extended Warranties

Manufacturers have their own requirements for issuing longer term warranties. We focus here on single-ply systems as that is the majority of the New England market and what we are most familiar with. This gives you some idea of the differences. EPDM systems: There are different methods to attach insulation and the EPDM membrane. Adhesive or screws/plates can be used to secure insulation boards. Adhesive (called fully adhered) or screws/bars/plates (called mechanically fastened) can be used to secure the EPDM membrane. It is possible to install both insulation and membrane unsecured then cover with round ballast rocks to secure both (called ballasted). For longer term warranties manufacturers will take a more active interest in making sure all the wet materials are removed. If the roof is to be entirely removed this is not an issue. A moisture scan may be required.

20 year systems generally have to use heavy duty fasteners on the insulation (and membrane if mechanically fastened system), enhanced perimeter (either with extra membrane or special metal details), enhanced seam details (extra EPDM over the seams and around penetrations), thicker or reinforced membrane and thicker insulation or cover boards. Fiberboard insulation is not acceptable.

25-30 year warrantees are not obtainable for ballasted systems – mostly due to the dirt that will accumulate between the rocks and dry rot the rubber (like car tires on an old car). Expect to have to completely strip the existing roof to the deck, utilize .060 or thicker reinforced EPDM or .90 mil thick non-reinforced EPDM. All materials used will have to be by the same manufacturer. No tie-in’s to adjacent roofing areas would be allowed. Enhanced perimeter, seam and penetration details are usually required. Pull-out tests to determine whether the deck will provide sufficient integrity to install the roofing system on are often required.

TPO systems: Most of the same rules that apply to EPDM apply equally to TPO with the main exception being less extra work at the seams. Since TPO (and PVC) seams are heat welded they are already about 3x stronger than any joining EPDM together. As the membrane already is reinforced, you can usually obtain up to a 25 year warranty with .060 TPO membrane. To get a 30 year warranty will require a thicker membrane (likely .080″ thick).

PVC systems: Interestingly you don’t find too many PVC manufacturers offering warranties greater than 20 years, even though their products have been around that long (and TPO hasn’t). The two PVC manufacturers Sika-Sarnafil and Duro-last both stack up equal or better than TPO in our opinion.

Previous steps:

If you are at this point you have hopefully read through our recommendations on how to check out your existing roof and prepare it to receive a new roof. Choosing what type of roofing system involves a lot of factors – existing substrate, functional requirements, warranty requirements, cost sensitivity and building codes. A 10+ year system would involve installing a new comprehensive waterproofing layer, possibly with additional insulation or substrate separation layer at a low cost. The difference between a 10-15 year warrantied system and a 20-30 year warrantied system is the 20-30 year usually has a thicker waterproofing layer, may have added redundancy at key future failure points like flashings or the roof edge, may require it be the only roofing system installed and the warranty costs more per square foot. 90% of our customers are happy with the 10-15 year warrantied system.

Functional requirements:

  • Is it important to reduce heating and cooling costs? It may not be if you have a warehouse or shop type environment. If it is important then how much will more insulation reduce the heating and cooling bills? There are different ways to figure this out – use EnergyWise from the National Roofing Contractors Organization or hire a professional to check the roof and/or the whole building. The best advice you can buy will be just an estimate. There are too many variables for someone or some computer program to say exactly what the savings for increased rooftop insulation are. The roof isn’t the only place that can lose hot or cold air. If you are serious about saving the energy bring in an infra-red camera and check the entire structure as well as any machinery in place. The building codes for New England for new roofs generally require an R value between 15 and 22, depending on how much window glazing there is in the walls and the location of the building. Isocyanurate insulation is the most cost effective insulation and it has an R value of 6 per inch. If the R value in your roof is close to the building code requirements it could be years before the return on investment from increased insulation is seen. Thicker insulation costs more in insulation material, thicker wood blocking at the perimeter of the roof to match the thicker insulation height and longer fasteners to secure the insulation to the roof deck. Check what you have existing on the roof and ask your roofer for a separate cost for thicker insulation.
  • Does the roof or area receive lots of foot traffic – choose strong insulation/underlayment materials and a tough waterproofing layer with redundant layers. Install walkpads, walkway rolls or pavers as well.
  • Are strong winds possible? This could occur from being near an ocean, lake or large empty field. The building height and the presence of a parapet wall (and how high the parapet is) around the perimeter of the building also can generate more uplift on the roofing system. If there is more wind make sure the manufacturers warranty specifies a greater wind speed so the design of the roofing system is appropriate.
  • Will the roof deck structure be able to support the new roofing system plus any snow load – if there is any question a structural engineer must be brought in.
  • Is there a plan to cover the roof with solar panels – again the structural load must be checked and the roofing system should be one that lasts a longer time. The solar panels may require a white roof to either cool down the panels for efficiency or actually utilize the reflected sunlight to convert to electricity.
  • Have you considered adding skylights – doing it during re-roofing saves on installation costs. Skylights can allow most lights to be turned off in the daytime. There are new types worth checking into (prismatic lenses, solar tubes).
  • Is the existing drainage adequate – if not add more downspouts, scuppers, interior roof drains, crickets (raised areas) to force water away from ponding areas. Tapered insulation may be needed on the entire area to generate correct drainage.
  • Are there areas in the walls that open up to create negative pressure on the roof (truck bay doors) – install an air barrier and extra insulation/waterproofing attachments in those areas. Make sure all roofing material will be secured to the roof deck appropriately.
  • Is a vapor barrier required – is the area a pool, sauna, hothouse, uses lots of moisture, etc. – check with a professional.
  • Are grease or oil products exhausted onto the roof – use sandboxes around the fans and special protection for single-ply membranes (PVC is much better than EPDM or TPO)
  • Is your building insured by FM Global – they will need to be involved in the re-roofing process.
  • Is the building a freezer or cooler – in addition to extra insulation certain roofing details need to happen at the roof edges and around all penetrations – make sure the roofer knows what they are doing or money will be wasted through continual energy loss.
  • Are there special color requirements for the perimeter metal that shows from the ground – Toyota dealers require all metal to come from one place – special orders – long lead times.
  • Are there areas where snow/ice can slide off the roof and cause injuries – discuss snow guards/rails. This is especially important on roofs with a pitch greater than 1″ in 12″ like metal roofs covered with single-ply membrane or coatings that offers less resistance to sliding snow.
  • Waterproofing layer – What are the choices?

    The 3 main choices for a waterproofing layer in New England are asphalt built-up, single-ply membrane and modified bitumen. Will a coating last 10+ years – maybe, but since we haven’t seen one do that we are not speaking to that option. We also haven’t seen a spray foam roof last 10+ years in New England – so we aren’t speaking to that option either.