I am a board member of my townhouse homeowners association and our townhomes are unfortunately very tall (need a lift or 60 ft ladder to access the roofs) and also the builder made the roof one single contiguous roof (unusual for townhomes, common for condominiums). As such, the Association is responsible for the roofs.

The original installed roofs, which are modified bitumen, are failing very early in life (around 7-8 years). The early failure seems to be attributed to both poor installation and lack of regular maintenance. We've been given different stories from different contractors regarding whether replacement is necessary, or repairs are possible... but even those who say repair is possible, they all say modified bitumen requires a minimum of annual maintenance, if not more frequent than that.

Unfortunately, due to the height of our roofs, it limits the number of contractors who can do the work or requires the expensive rental of a lift. So we are going down the path of replacement, and want to install the roof that will require the least maintenance.

Which flat roofing system is the most maintenance free?

  • In the UK this would be covered by the NHBC warranty, I am amazed anyone would buy a new home without such cover. (We expect in the UK for modified bitumen roof to last well over 10 years, but it is common for them to last under 20 years. My house insurance excludes any water damage from a bitumen roof that is over 15 years old)
    – Walker
    Oct 28, 2011 at 13:06
  • 2
    Is is normal for builders in the USA to get away with such poor standards? (I would expect a townhouse to be built with a roofing sysem with at least a 60 year life.)
    – Walker
    Oct 28, 2011 at 13:09
  • 1
    @walker much of america's housing in the past 30 years is pretty much popsicle sticks and duct tape. Builders of our sprawling suburbs tend (not all, but many) use the absolute cheapest materials and adhere to the bare minimum of code requirements. We're a nation that seems addicted to square footage rather than architectural and structural integrity.
    – DA01
    Oct 28, 2011 at 14:47
  • Also, I'm no expert on roofing, but my understanding is that rubber based products are far superior to the bitumen options.
    – DA01
    Oct 28, 2011 at 14:49
  • 1
    Regarding warranties... we've been told our warranty was voided by not doing regular maintenance. Possibly fightable in court, but legal fees aren't cheap where we live. And regarding the build quality, the builder is bankrupt anyway.
    – dissolved
    Oct 28, 2011 at 18:13

2 Answers 2


I am not an expert in this type of roofing, I do however have some questions and recommendations that may help you get the right answers.

First the questions. Is this roof drained with an internal system or scuppers along the edges? How large (square footage) is this roof? What part of the country are you in? Have you consulted an industrial/commercial roofing specialist?

Here in the north country, most flat roofs on larger buildings are treated in a bonded/welded rubber, neoprene membrane. All the edges, sidewalls, plumbing vents, chimneys etc must be properly flashed and sealed with bitchethane and bonded to the flat covering. It is also very important to know that a flat roof is actually not perfectly flat. They must have some designed pitch to a drain point/s. Any area that allows standing water is potential source for leaks. Proper drainage is essential and will prevent the majority of future leaks.

Since access to the roof seems to be an issue for you and the contractors you have consulted so far, consider the following:

Only deal with a contractor that owns or regularly uses a bucket truck or man-lift and is used to working on taller buildings, and has the proper safety equipment and trained personnel to safely handle the job and materials.

Look at options to install a dog house access on the roof. If there is no common area where one can be installed, explore the possibilities of an external attached caged ladder. Some method of easy access will allow safe, quick inspection of the roof.

Solving your problem should be fairly evident to a competent industrial/commercial roofing contractor. You may not like the answers you get, or the costs to fix the situation, but if you do it right this time, you will save money in the long run, minimize potential interior damage, and protect the value of your property. Good luck.

  • The roof is ever so slightly pitched as you said. Pitch goes from front to back. Unfortunately, most of the homes to pool water at the back of the home. I don't know what you mean by "drained with an internal system or scuppers along the edge", but the water is suppose to drain into a gutter on the back side of the house.
    – dissolved
    Oct 28, 2011 at 18:19

I'm glad you asked this question as I work in the single-ply roofing industry. :)

I would recommend a pvc-based single-ply roofing system. My particular manufacturer offers the best warranty in the industry at 15 and 20 year lengths that guarantees both the material and installation (it discludes third-party damage, which would be like an AC guy putting a hole in the roof), is VERY thoroughly inspected by a QA representative from the manufacturer, who then issues the warranty if it passes the inspection.

These roofs are essentially meant to be maintenance free throughout their expected life spans. If any first or second party maintenance DOES happen to come up, which happens less than 1% of the time, then the maintenance is performed by a representative from the manufacturer or an authorized contractor at no cost to the building owner.

I've inspected many HOA owned buildings and townhouses and this is definitely a great solution.

  • Is PVC similar to TPO?
    – dissolved
    Oct 28, 2011 at 18:20
  • It is similar in terms of the way it looks and is installed, but PVC is an alltogether better product. TPO is an unreinforced product that is weak structurally, tears easily, and lasts 5-10 years at best depending on climate. However, it is roughly half the cost of PVC. A good PVC product will be reinforced, strong, and last 15-20 years.
    – Tim_P
    Oct 28, 2011 at 19:06
  • 20 years still seems a very short life for a roof!
    – Walker
    Nov 1, 2011 at 11:30
  • Not for a flat roof with a warranty it isn't. Maintenance costs for "traditional" flat roofing systems (modified bitumen or a built-up-roof) tend to add up over the stated lifetime of the roof, with the maintenance costs snowballing upwards at about the half-way point of their lives. As I stated before, a good quality PVC roof will have minimal maintenance costs associated with its upkeep. In fact, as long as you choose a manufacturer with a good warranty, the only maintenance required is an annual light powerwash of the roof and cleaning of the drains and/or scuppers.
    – Tim_P
    Nov 3, 2011 at 2:21
  • Which leads me to another point. Energy efficiency. A white PVC roof can be anywhere from 80-95% reflective, leading to significant energy savings due to keeping the interior of the building much cooler. On a large scale like multiple apartment buildings, we're talking about savings in the tens of thousands of dollars per year, assuming you do that annual light powerwash.
    – Tim_P
    Nov 3, 2011 at 2:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.