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What type of roof system to install

12 replies [Last post]
Joined: Feb 10 2004

Just looking for opinions on whether to install a T&G roof with rigid foam insulation underneath or doing a sprayed foam roof. While my house isn't an Eichler, it is post modern with the typical problems associated with having a flat roof and/or shallow pitched roof.

We do have quite a few squirrels and cats scampering across our roof as well as the ocassional bird having its meal up there. My concern is the comments I have read on the Eichler message boards regarding the occasional bird "pecking" on a foam roof and creating holes. Should I be concerned about this in my decision with which type of roof to install?

Joined: Oct 10 2003

Hi Wango,

There's been alot of discussion on roofs over the past couple months including some good info on different kinds of insulation vs roof materials, so it might be good to check out some of the older threads on this board.

I got a foam roof put on last November over an aging tar & gravel.

some posts to start with;


Joined: Mar 23 2003

hi Wango , I had my roof done with foam insulation and tar and gravel and it has help up for 12 yrs with no leaks. Most tar and gravel will last up to 20 yrs depending on how may layer of felt paper is apply. For my roof i had 4 layers of felt paper. If the job is done right like all roof jobs it should last at least 20 yrs. good luck tom

Joined: Jan 4 2004

You really have to prioritize what is your primary concern, and work from there. If cost is your #1 concern; a single ply modified bitumen over insulation is a good way to go (though many roofers are of the opinion that it is not the best system for completely flat roofs) is a good way to go.
Foam roofs have advantages that tar, modified bitumen, Duro-Last, and steel roofs don't have, but also have disadvantages as well.
As far as advatages go:
1. Self insulating; (particularly helpful if you have a lot of plumbing and conduit to cover) doesn't require insulation but is usually applied 2"-3" thick, and will only give the "R "value comparable to insulation of a like thickness.
2. It is a lighter , more flexable material than tar based products, so it reacts better to expasion and is less brittle. I don't buy any of the info about the fact that it is "better for the house because of the weight vs. tar; roof framing is generally calc'd for loads exceeding the weight of the dead load (weight of the roof plus framing), and because the material is distirbuted fairly evenly, the weight is also spread out evenly.
1. Maintenance.
Foam needs to be re-coated every five years or so to create an optimal life span of the roof; that must be factored into the overall cost of the roof.
(plus the hassle factor- but you can assign your own value to that), and repairs are trickier.
2. Durabilty
Foam roofs generally don't have the same life span as tar roofs (foam 10-15 yrs, tar 12-18 yrs, mod bit 10-14 years, Durolast claims to be a 25 yr roof, steel can go longer with proper maintenace). They also are too thick to re-coat multiple times (some municipalities allow three roofs before a tear off is required, some allow two), the catch is, if you lay a thick (3+ inches) layer as your first roof to gain insulation, then it is likely that you will be unable to apply foam as a second roof; when it is time to re-roof, roofers will tear off a roof if it is foam, period.
3. Application
Let me preface this by saying that there are many reputable roofing companies out there that do a fine job of applying foam; however after talking to a roofing consultant (who often is an expert witness in civil suits)
I was told that the most common roof about which he provides testimony
in open court is, yep, foam. One of the reasons is that if the application is done incorrectly, can result in failure, and since bringing the foam truck is costly to set up, many foam roofers are inclined to avoid a second set up (as well as variety of other reasons, I'm sure). So thoughly check out your roofer (CSLB, BBB, references, etc.)
After insulation, (for the initial installation) tar can cost more than foam or M.B., Durolast costs more than the other three, ands steel is usually more expensive than all the others. Also, all these snipets of info are generalizations relating to my experience from the perspective of a general contractor; I'm sure that there are others that may have had other experiences. So , if you are taking the long term perspective, you have much to consider. Good luck and happy hunting.


Joined: Mar 22 2003

Welcome to the community, Wango!

You may want to get a copy of the Summer 2003 Eichler Network Newsletter. You can order it from this site, by clicking on the Newsletter Lowdown link at the top of the page. It is a roofing special and in it, I discuss the 5 common types of roofing systems for flat or low-sloped roofs. Each one is discussed in terms of advantages and disadvantages.

We installed a foam roof 6 years ago, after getting tired of trying to get the tar and gravel one to stop leaking. Once they develop leaks, they are almost impossible to detect and fix, since the water may enter in one place and exit another (could be clear on the other side of the house).

To Renman's comment about foam needing to be recoated every 5 years: Dura -Foam, which did our roof, is now claiming that based on their experience and testing, the recoat only needs to be done once, at the 5 year mark and that is now the protocol they are following. I do agree with Renman in his observation that foam installation is very technique sensitive. If you go with a company that has poor quality equipment, people, or practices, your roof has a greater liklihood of failure. But correctly done, foam roofs are hard to beat - which is why they are so common for industrial applications and have been for many, many years.

I am especially fond of foam, since ours has worked out so well. It made a huge comfort difference during the hot winter months, is light weight and therefore better for the structure than having 1.5 tons of gravel up there--you get a light, waterproof, and insulating roof all rolled into one.


Joined: Mar 23 2003

Tar and gravel is the best type of roof to install it has been around for a long time and its here to stay. It is a proven roof that is still used widely in the industry unlike foam and other types of roof which is not proven.

Joined: Mar 24 2003

Since no one has presented any scientific evidence one way or another, it's really not possible to say what roof is "proven". Homeowners only have their own experience, contractors may or may not have a financial agenda to recommend one type of roof, and the fact that something is long-time industry practice doesn't necessarily make it better. I'm sure when gypsum wallboard first appeared there were a whole lot of contractors out there who were telling customers to stick with lath and plaster, a "proven" "industry standard" wall system.

Having said that, let me add another anecdotal recommendation for a foam roof on an Eichler. Ours has been leak free, hassle free, easy to clean, warm in the winter and cool in the summer for over 10 years (with one recoating). I wouldn't hesitate to recommend a foam roof.


Joined: Mar 2 2004

Hi Wango,
Dura-Foam is now in it's 24th year and has done a second recoat on only 3 Dura-Foam roofs. I gave a quote yesterday on a seven year old foam roof from an infamous ex-competitor. It had been extensively repaired and recoated two years ago. In spite of this expense, it must be replaced. ( We would not have tried to repair this roof )
How do you digest all this divergent information?
I believe Roofing and other Contractors are honestly giving you their perception of their own experience, or what they've heard. Have you ever heard a Contractor say that he did not know?
I believe tar and gravel roofs last 8 - 12 years with many exceptions for those installed on sloped roof decks.
I believe that foam roofs are either good or bad when installed.
I believe a good foam roof can inexpensively last indefinitely
I believe that quality coatings are worth the expense
I believe that we have installed more foam roofs around here than everybody else put together.
I believe that our thousands of our customers believe the same things we do.
Some Eichler owners get three estimates. The information doesn't agree, or add up. They get two more estimates, trying to make sense of it. Now things are even more confusing. How do you know what to believe?
Contracting is not Rocket Science. What if Engineers had as many opinions about materials as roofers express?
Contractor Education is done solely at the expense of the customer. The requirements for getting a Contractor License are
- 4 years experence in the trade
- Pass a simple test on Law
- Pass a simple test on the trade
- Claim to have $2,500 in working capital
- Are not currently incarcerated for committing a felony
There is no required training in chemistry, physics, logistics, safety, materials/procedures, building code requirements, contract law, human resources, accounting, finance, equipment, hazardous materials, fire safety, public relations or spelling.
To do a good job and be successful, a contractor must be capable in all these areas (except spelling). All of us feel that an auto mechanic is more knowlegeable than a roofer, but who really needs to know more? An auto mechanic often makes a diagnosis and changes parts.
Here's the real issue with Eichler Roofing Unlike shingle or tile roofing, where the factory made pieces are nailed down on a sloped deck; Foam and tar and gravel roofs are made in the field. Tar roof components are layered and pieced together. Foam is actually manufactured by equipment on site as the metered materials mix coming out of heated hoses. There is a lot of potential for error...or should I call it education.
These comments won't offend any of the contractors who are associated with Eichler Network. The comments may offend the under funded, under-educated group with which we compete for your business.

Joined: Mar 9 2004

Randy and Dura-Foam installed a new foam roof on an Eichler that my wife and are redoing. I highly recommend Randy. He is professional, easy-going, honest and knowledgeable. Dura-Foam stayed within their estimate and provided very good service. The foam roof has made an enormous difference in noise and insulation. Clearly, since it is a new roof, I can't comment on its durability. However, it is totally water tight (which wasn't the case with the old tar/gravel), and I believe Randy that with proper 5 year maintenance, it will last for a long time.

Hope this helps.



Joined: Apr 10 2003

I've seen some of the Alexander Homes in Palm Springs with a white roof that looks very much like a rock roof but it you look closer it looks like its foam/plastic with a nubby gravel/tar roof like appearance-is this foam or DuroLast or some other type of product? The problem I have noticed with gravel/tar roofs is that over time it all seems to wash away-my aunt's house always had this line all around the house of pink gravel after each rain that was perfectly aligned with the overhang. Last time I drove by (the no longer live there) it had a composition roof (roof was lo pitch not flat) along with every other house in the tract.

Wishing for modern home.

Joined: Mar 21 2003

Years ago I had a house with a pitched gravel roof. That house did have the problem of gravel coming off and depositing on the ground around the eves. Our flat roof Eichler with T&G roofing does not have that problem.

As far as durability of T&G (and maybe other roof types), if you live in Sunnyvale you don't have to go by guesses and hearsay:

1) Go up on your roof and look around to see what your neighbor's houses have on them. If it is T&G you can be pretty sure that the previous roof was also T&G. If it is not T&G you might ask the owners if they know what was there before the current roof.
2) Recall that re-roofing requires a permit. Since it is likely that any re-roofing has been done by a licensed contractor, you can have some confidence that permits were pulled so the roof life can be deduced from the permit history of the house.
3) Next go to the City of Sunnyvale's web site and navigate to the building and safety section. Key in the addresses of the house(s) in to the area for checking permit history. You will see how often a permit was pulled for re-roofing which will tell you how long the previous roof(s) lasted.

In my neighborhood it looks like the original T&G roofs usually lasted about 20 to 25 years. If I recall correctly, in some cases the original T&G lasted over 30 years.

As near as I can tell, none of the newer style roofs in our area have failed yet. But none of them are over 10 years old yet either.

As a slightly off topic point: On a recent return flight to San Jose we flew over my neighborhood. I noticed that the neighborhood looked quite different from the air than the adjacent non-Eichler neighborhoods because of the preponderance of white roofs. Looking about some more I notice a few other white roofed neighborhoods located within a couple of miles of our house and recognized them as other Eichler tracts.

Joined: Jan 29 2004

I love my foam roof. I've been shopping for homeowner's insurance, and got this interesting email yesterday:

>Hi Robert,
>I'm sorry, but Farmers Insurance doesn't accept foam roofs.

So that might be a tiny added consideration for you.


Joined: Mar 9 2004

That is odd, b/c we have Farmer's and they do not have a problem with our foam roof....


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