Does this roof need gravel?

The roof covering is a smooth black surface with tarred/sealed seams. No granules. Is it OK like this or is it designed be covered with gravel or something? Thanks in advance.



Evening bump.

Nobody has an opinion on this?

Looks to me like it needs some type of ballast. It’s difficult to say without knowing what type of material it is. How new/old is it?

The building had extensive remodeling done within about 2 years, but the rusted edge flashing and cracked roof covering surface made me think the roof covering was older. It looked kind of like flashed down modified bituman, but had a smooth surface. I suspect that it might be the stuff they put down below a gravel covered roof, and they didn’t put the gravel on top. It is a only about 500 sq. ft.

Or it could be built up with a few layers of top coat…really hard to tell from the pictures…jmo…jim

Ralph, I found this for the Scotts Valley Ca. region as types of flat roofs.

The first step in deciding what is right to cover your flat roof is to view our list of coverings:

  • Fluid applied systems - sprayed on systems which are highly reflective and reinforced with polyastere fabric (in liquid and gel form).

  • **CPA Single-ply membranes - **40 to 80 mil white rubber membranes which can easily be installed over firm, stable, and dry sub-surfaces.

  • **Modified bitumen applications - **modifiers are added to the asphalt in these sheets in order to provide a rubber-like membrane.

  • **Built-up roof assemblies - **multiple layers of hot asphalt with layers of fiberglass or modified rubber sheets.

  • Polyurethane foam resurfacing applications - installation of acrylics, urethanes, or hypalon over an existing foam roof.

If I had to guess it would be this one.

My area is easy, roll roofing, shingles, EPDM, copper, metal. All done. ha. ha.

Hope that helps a little.

Marcel :slight_smile: :smiley:

Looks like an EPDM roof. Google it - you will find a lot of information on it

I agree, looks like EPDM. Does it feel like an inner tube from a tire? Ballast would help secure it down.

Can the structure hold ballast?

Hi to all,

there are several methods of fastening EPDM roofing membranes dependent on the application, some could use ballast, but not normally on a fully adhered system.

Here’s a good link about the subject:



Why would you add ballast to an apparently functional installation?
That roof has been there long enough to show wear/degradation and it just may be time for replacement evaluation based on appearance and other information.
No leaks were mentioned in the post.

Is it an inspectors job to make a ballast installation recommendation with/without further insight as to the original design/material/installation?

If the roof installation/material/wear is in question have it evaluated by a qualified roofer.

If you don’t know what the material is and the proper techniques for it’s installation, it’s time for further education and a trip to a local supplier to get eyes/hands on experience and samples. jmo, I’m not pointing fingers at anyone just a simple suggestion.


I agree Barry, the ballasting question is a bit complex and somewhat contentious, in fact I see more incorrect ballast than correct ballast (crushed rock rather than river-run stone), no adequate gravel stop, ballast on roofs subject to windstorm etc, etc.

Down here a ballasted roof is mostly a liability due to hurricanes.

It is definately an area for further study for those doing commercial inspections.



That is all correct Gerry, and here in Maine the Ballast system is no longer used.

EPDM roofs are now all fully adhered.
It has been proven over the years to be better.

The ballasted systems used 10#s of riverwashed stone which is no longer available from rivers and has to be screened and washed round stone.

The weight of the ballast increased the cost of the buildings drastically due to steel structure or wood framed roofs.

Gerry, look at the original post, look at the first picture and I don’t think that is a EPDM roof.

I listed five types of roof systems from a roofing company in the area and guessed what it may be.

You might know.

Marcel :slight_smile: :smiley:
You might recognise it since that was in a hot climate also.

I don’t think Ralph is even talking about ballast.

Hi Dave, ain’t thread drift a wonderfull thing :wink:

Marcel, I had just looked at the second image not the first, I think you are correct about the Mod-Bit, normally in that application I would expect to see some form of UV protection over the surface, either a cap sheet, granules or a reflective “paint” coating.



Thanks for the replies. I have inspected over 1000 homes and have never seen a smooth surface roof like that one. This is an isolated area and we don’t get a lot of variety.
I was worried about the UV protection. From the internet link provided, it did seem like it may have been EPDM.

Good point, The structure load capacity should be taken into consideration as well.

Just saw this post, but yes that sure looks like rubber to me.
Obvious by the curve at the parapet wall.
Unusual to see it wrapped up and over.
No coping.
Wonder how they terminated it on the front ? Cant be attractive.
EPDM roofs have inherient uv protection .

For those wanting more Professional Roofinginformation you can subscribe for free

I get that mag every month.
Lots of ads but a few good articles.Plus it is free as Barry said, for the hard copy.