On Sun, 12 Jul 2015 05:32:12 +0100, Archibald Tarquin Blenkinsopp
wrote:

I thought I would give it a coat of paint to see if I could stall the
inevitable [one or two sunken its hold water].

Is it leaking? If not and you know it's in poor condition yomping
about on it isn't going to do it any good. Sunken bits holding water
are not a problem, they aren't leaking!

Why do you think a solar reflective paint is going to seal it or make
much difference to an old roof that will already be degraded. Bung it
on a new roof, maybe. Indeed if it is solvent based and the existing
felt is a bit weak or cracked the solvent will penetrate and may make
matters worse.

--
Cheers
Dave.