waterproof grout all over?

[dabaldie]

i'm fully tiling my bathroom.
some parts of the wall (1905 house), are damp when i remove the old tiles (blown) but appear todry out quite quickly after.
would i be better using a waterproof and grout for the entire job, or should i just use normal non waterproof adhesive/grout in the middle areas that wont get wet? (no condensation etc), and let the wall breathe?...
or should i just seal the whole wall.
I've looked into what is causing the damp but cant figure it out, but i did notice the old owner has replaced the flashings above , i can only guess they tiled before letting the wall dry fully after replacing the flashings.

 

[masona]

I've looked into what is causing the damp but cant figure it out, but i did notice the old owner has replaced the flashings above , i can only guess they tiled before letting the wall dry fully after replacing the flashings.

It's best to find out what is causing the damp to save you money in the long run.

 

[dabaldie]

believe it or not i'm a civil engineer and do B and CE inspections.
as i said i've looked for the cause of the damp and think it must have been trapped in the wall by the waterproof adhesive.
the external walls are brickwork which have had a waterproof render applied so any water in the wall is really trapped.
what i dont want to do is leave the walls untiled for months to let the walls dry out properly, i just dont have the time, i was wondering if the mixed grout method might work?

 

[masona]

How about hiring the industrial heater for one night, that should dried it out straight away.

 

[dabaldie]

cool good thinking.. i did notice last night that a small patch of the damp had dried overnight so it cant bee tooooo bad.
i was going to use the dehumidifier too... but last time i did that i dried the toilet trap/ the showertap and the sink trap out...jeez that stank!
might try the old cling film over trick this time...

remember to take the cling film off

hehe