This house has a flat roof. The current owner uses drop ceiling in
many places so that he can route wiring, AC ducts and electrical and
lighting outlets through the roof. I don't like panelled drop ceiling
so if I get this house I will be removing them.
Which means I will have to find another way to route wires and ducts on
top. The roof has very little room a few inches with insulation that's
all. The second story on the left side actually has an exterior door
where it opens and one can walk on top of the flat roof.
What I am wondering is how easy will it be to build a new flat roof on
top of the existing flat roof (but elevated 24" or so higher) so we can
use that room to route wires and ducts. Then I can cover the roof with
flooring material (tiles or slates?) and put railings around it's
perimeter so the roof becomes a sun deck.
Will this be a prohibitively expensive project to do? How would I
determine if I can put new flooring on the roof - whether it was
designed to take this added weight or for someone to walk on? Any
I know this is probably more a question for a contractor, but this is a
house I plan on putting an offer on and I need to get as much
information as possible about what can and cannot be done.
Thanks in advance,
Too much change for just a cosmetic concern. Find a house you like better
and spend your money and efforts on something you will enjoy and will pay
back big like a fancy bathroom or a really nice kitchen.
Sounds like it would cost every bit as much as tearing the roof off and
building a new one from scratch. It can be done but it is a major
renovation for modist gain. Might as well raise it 8 feet, the extra cost
of lumber for the walls might not be such an add on but the extra SF added
to the house would push the permit price significantly higher and result in
a major tax reassessment.
The load carrying ability of a flat roof is largely determined by the size
of the joists and the span they need to cross. Normally a roof only carries
a static load, so to stabalize it for a dynamic load like people walking (so
it does not wiggle or make too much noise in the house) would require
additional bracing and stronger decking than normal.
With a careful design - one that pays attention to high winds,
flashing, drainage, and load paths - it might be done.
The problem is one for a really careful contractor or IMHO for a
The new roof surface will be higher than the existing roof surface and
so access to it has to be considered.
Code requirements and documentation for a building permit are
This does not follow. If you have the available headroom, you could
just as easily take down the drop-ceiling, and build a sheetrock
ceiling at the same height.
But if you want to make the roof walkable, don't like the ceiling,
and hate the mis-named "mansard" bit, then by the time you fix
everything peicemeal, you'll be better off just taking the
whole roof off and building what you want.
Have you looked above the drop tiles with a strong light? Betcha find
evidence of old water leaks. The drop ceiling, and the exterior door opening
from second floor, tell me there likely was a deck up there (probably just
planks on sleepers), and the original hot-mop roof started leaking under the
sleepers. Did house have central a/c when built, or wall units? House looks
early 1960s, so wiring would have been minimal by modern standards, and if
it was an beam-and-T&G ceiling, any hanging lights would likely have been
fed by raceway, or a notch on the top of the beam, or possible box-section
faux beams. To replace the the tiles, you can always go to a high-velocity
duct system, and fit it all in a 2x6 framing grid, covered with drywall,
jammed up tight to the old ceiling.
But like the others said, you need a site survey by a qualified architect or
engineer, to determine what is actually there, and what changes are
realistically possible. Unless bidders are lining up, the seller shouldn't
care about a non-destructive inspection.
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