# Flat roof and insulation quandry



## paredown (Mar 20, 2009)

First time in the roofing section, although I've posted a couple of other problems regarding my ongoing renovation.

Our house is a long "L" shape--think three boxes, flat roof section facing street (bottom of L), turns onto a peaked post and beam center section and finishes with a slightly jogged second flat roof section. House was built in 1963.

Front flat roof section is the current project; it clearly had roof leaks at some point then a "new" flat roof was installed (sometime in the '80s) by a guy who apparently was the last good BUR/tar & gravel installer in the area. All copper flashed, and I believe he added a shallow pitch from center line out so there are scuppers and downspouts on the front, and he added "cut-throughs" on the back flashing to drain onto the transition section of the middle portion of the house.

The roof is not leaking--a tribute to a good install I think. But...

*Problem is--I need to insulate*. (I snagged an image off the web that will give you an idea of the roof deck construction--but imagine it with almost no insulation!)

Option 1: 

Tear down the inside ceilings (and sacrifice the plaster skim coat that my dear wife loves), remove the 2" reflective (?mineral wool; fiberglass?) insulation, retrofit R19 (2x6 and need air gap below deck) from below, re-drywall and deal with the roof later;

Option 2:

Get savage, strip the existing roof and deck (DIY?), tidy up some wiring & vents while open, maybe add a porch extension, spray closed cell foam from the top, guaranteeing a better insulation job (eg around blocking). 
Then DIY a new deck. 

Then a professional roof install with new tapered board, new counterflash (love to re-use the existing flashing if possible since the budget won't extend to copper), and single sheet (EPDM?). 


Option 3:

Abandon the flat roof, and do a low pitched shed-style roof using 2x6 rafters with the high side at the front. New deck and a DIY-friendly roofing material TBD (I've done both metal and shingles before). There are some aesthetic reasons for this choice, but this would mean pulling a permit, etc. And I'm working by myself...

For financial reasons, option 1 is the most attractive, but nothing worse than doing interior work, only to have the roof leak anyways (and nothing soaks up water like fiberglass.

What sayeth the wise roofers of the board?


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## paredown (Mar 20, 2009)

Not the best, but here are some pics of the section we are talking about, and a couple of shots of the roof, and one of the downspout install.


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## federer (Aug 20, 2010)

i have the same issue with a flat roof. what the insulation company said was to tear off decking so they can get in there and blow insulation, then re roof


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