DIY Doctor UK DIY Forums

Hello, I built this shed and put an inexpensive felt on top (hoped to add fibreglass but was over budget).

Felt was good for last 6 months then in the last week these water stains turned up on the sides...nothing on top. Cold roof and no leaks inside as far as I can tell.

Anything to be concerned about? Ta

Hi hobjob
Most likely causes by dirt in rain. Leave it for another 6 months and it will probably wash out. You could try hosing it down for a quicker solution.
Regards S