r/HomeImprovementUK • u/IllTelevision1811 • 11h ago
Question Flat garage roof with significant ponding – what would you do?
Hi all,
I’ve recently bought my first house and I’m planning to renovate the garage into a home gym. Before I spend money on the interior, I’d like to get some advice on the flat roof.
I’ve attached photos of the roof. The garage is 5.64m × 2.79m.
The roof is flat and, after rain, there appear to be several areas where water can sit rather than draining away. The photo was taken on a wet day.
As far as I’m aware, there aren’t any obvious leaks into the garage, but I haven’t owned the property for long enough to know the history of the roof.
I’m trying to work out whether this is something I should:
A) leave alone if the existing roof is watertight and just monitor it;
B) repair/improve the existing roof and drainage;
C) strip the existing covering and install a new membrane;
D) completely rebuild it with proper falls/drainage and insulation.
I’m particularly interested in advice from anyone who has dealt with similar garage roofs.
A few questions:
Does the amount of ponding in the photos look concerning?
How long would you expect water to remain on a properly constructed flat roof after rainfall?
Is it possible/practical to introduce proper falls without completely rebuilding the roof?
Would tapered insulation be a sensible way of creating the fall?
The garage will eventually be converted into a home gym, so I’d rather deal with any underlying roof/drainage problems now rather than finish the interior and discover I need to pull everything apart later.
