On Oct 15, 7:16 pm, Jimbo wrote:
On Oct 15, 9:30 am, dpb wrote:



Jimbo wrote:
Most of my house (located in Toronto, Canada) has a flat roof with a
reasonable run off. It was built in the 20's and the roof is BUR with
various layers added over the years. Some recent damage got me
looking at the roof in preparation for winter. When I peeled back the
membrane (looked like old ungranulated torch on), I noticed all the
fiber board (cover up) boards were soaking wet. My question: is it
worthwhile taking off all the wet fibreboard and replacing it with 1
or 2" polyiso and then recovering? Or should I just replace the
fibreboard and recover with granulated torch on or roll on?

You should look at this from two points of view.
1. The roof you repair/recover, is best looked at in the long term.
Roofs are expensive and need to be done just once.
If the base is still usable, then merely covering it with fibre glass
will give you an easily repairable roof good for forty years or more.
This roof will be good enough to walk on and will not be effected by
any ice dams that may form.
2. Any insulation needs to be laid on top of your lathes and plaster
ceiling, where it will give you maximum saving in heat, and therefore
money. Sprayed foam will find its way into every odd shape and hole.
It is a tight fit, no holes equal best heat saving. Also you can stand
things on foam without it deforming and loosing its insulation
properties, five inches should do the trick. Leave the loft cold,
unless you live in it.
Perry