I've got a roof terrace which was constructed about 20 years ago over the
rear addition - it was previously a tiled sloping roof. All specified by a
decent architect and carried out by (supposedly) the best roofing
specialists in the area.

The construction is marine ply over joists with chicken wire surrounds
covered in asphalt. The upturns have lead flashings, and the main surface
GRP concrete tiles - IIRC called promenade tiles. Looks a pukka job.

Has been absolutely fine despite heavy use, but now a couple of tiles
have lifted along one edge by quite a lot - an inch or so. But aren't
loose. Like as though the asphalt has swelled in some way beneath them.
Isn't leaking or anything - but I'm concerned as to the cause and a way of
sorting it. I can imagine full replacement costing both arms and both legs.

--
*I was once a millionaire but my mom gave away my baseball cards

Dave Plowman London SW
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Dave Plowman (News) wrote:

I've got a roof terrace which was constructed about 20 years ago over the
rear addition - it was previously a tiled sloping roof. All specified by a
decent architect and carried out by (supposedly) the best roofing
specialists in the area.

The construction is marine ply over joists with chicken wire surrounds
covered in asphalt. The upturns have lead flashings, and the main surface
GRP concrete tiles - IIRC called promenade tiles. Looks a pukka job.

Has been absolutely fine despite heavy use, but now a couple of tiles
have lifted along one edge by quite a lot - an inch or so. But aren't
loose. Like as though the asphalt has swelled in some way beneath them.
Isn't leaking or anything - but I'm concerned as to the cause and a way of
sorting it. I can imagine full replacement costing both arms and both
legs.


IMHO and from past experience once the
promenade tiles start to lift you can expect
to lose both arms and legs very quickly.
usually there is only one thin layer of felt
under the tiles which are hot tar stuck
down, still you have had 20 years to save
for its replacement.* ;(
\0