Gotta like a spring-loaded roof hatch

Gotta like a spring-loaded roof hatch that isn’t locked. :cool:, a beautiful roof and a nice view of Mount Baker, Washington.
And a Sept 11 moment of silence.

John Kogel


Nice pic John, most of the hatches I get to go through either don’t want to open or bite your fingers when the lid closes.

As for the roof covering, it certainly looks shiney and new, but I’d question the lack of cant rail where the flat roof transitions up the parapet wall, that covering will crack along that interface.



Thank you, sir. Good point, all the inboard structures have cant strips but there are none along the outer parapet wall. This may have been a Tar and Gravel roof originally, BTW. The drains are in depressed channels along the outer walls.
The important thing for my client buying the condo unit was, yes, the roof has been done. :cool:



Do you expect to see cant strips on all flat roofs and do you write up missing cant strips if there are no seams at the transition area?

I’ve done many commercial flat roofs in Boston and many do not have cant strips installed. They do continue with the rubber right up alongside the parapet with no seams involved. I don’t have an issue with this. If you do, I’d like to hear your reasoning.

Hi Dave,

no I don’t write them up on some membrane roofs, it depends on the manufacturers installation instructions, however I write them up on all modified bitumen & T&G roofs, none of the ashalt based systems have the flexability to cope with the differential expansion between to roof and wall intersections, and they will fail quickly.



That’s what I thought.

EPDM is the only roofing material that will transition properly and fold at parapet without causing an issue. But… do that what another roofing material and you’ve got imminent issues.

Thanks for explaining that Gerry.

If there are any good links , going into detail on the above , I would appreciate them.

Try this Robert

Thanks Greg.

Gotta keep up with that tech talk.

Yell at me if I am wrong , but did you mean Termination Bar.?

Thought I would add that Gerry is correct in his assessment.
I install roof hatches like that pictured frequently.

One thing I can’t see is walkway pads to the equipment, and stepping out of the Hatchway.

Usually, those are required, but not knowing this type of roof, it might not.
The other safety item that is sometimes present in new hatchways, is a retractable hand pole that retracts in and out of the hatchway for going up or down the ladder.

I don’t know if you see that many of them.

Below is a link from Firestone Rubber guard that shows all the flashing details for an EPDM Roof.

This link will provide you all with flashing details for the Bitumen Products.
As you can see, cant strips are required almost everywhere with this product.

As Gerry said, without them, the expansion differiential is enough to make the joints crack and leak in the first year of their application.

This link might be found useful for information also.

Hope this helps.

Marcel :):smiley:

From these two illustrations, a wide metal flashing is another possibility?
They may have torched-on right over the flashings.

Thanks Marcel , now can you tell us or me , why not continue the material up over the parapet rather than use a terminater bar half way up.?

Bob, in most cases where a termination bar or reglet is used the construction of the parapet wall is concrete or brick for a reglet, and some other rain sheild cladding for the use of the termination bar.

Dependant on the construction, there is sometimes no need to run the roofing membrane all the way to the top. This just adds to the cost due to redunancy in material serving the same purpose.

Hope this helps.

Marcel :):smiley:

Always follow the money. Hahaha
Thanks Marcel.
I have always wondered about that.

John, your 0106.jpeg is IMO as bad as just running the mod bit straight up the wall, as it is a 90 degree bent single layer it will still fail very quickly. I have the same illustrations myself, but have never seen one done like that, and would write it up if I ever did.



Thanks Gerry. I will agree with your judgment on this one, as I am not quite smart enough to disagree. Or dumb enough, either. :p:p