How to tell whether leak has been fixed successfully or not

[tb123]

Hi

Wondring if anyone can advise me...

I had a leak in my roof, and water was dripping down and caused a crack in a bedroom wall.

Builders came and did some work on the roof, but the crack appears to be widening and I'm worried the leak hasnt been dealt with fully.

Can anyone suggest the best way to tell whether the leak has been dealt with 100% successfully or not?

E.g painting over the crack and seeing if the paint discolours, or any other suggestions would be gratefully received?

Thanks

tb

 

[Nige F]

Rub some Anhydrous Copper Sulphate salts into the crack when you`re sure it`s bone dry. any water will make them turn blue. Learned that in the 60`s @ school Then ask on painting forum about cleaning the blue stain

 

[^woody^]

The crack will widen as it dries out. It does not widen because it gets wet.

Tissue paper or some dry dust from the floor on your fingers, will tell you if it is wet

Depending on the amount of water, it wont fully dry for several weeks

 

[Dit]

My builder got his helper to pour a bucket of water on the repaired area or the roof, while he watched from within the loft space for leaks.

 

[HaydnExport]

a bucket of water would be no good as a test of a leak is the leak was caused by wind . what kind of roof is is? slate, tile, flat lead? a pic would be most helpful

 

[--tom]

Test for pitched roof leaks with a hose pipe.
Why should a roof leak cause a wall to crack? Perhaps the water entry is thro the brickwork of the wall in question?
Much more info reqd.