builder or ex builder, I need advice.

Think you should hooked the van up the car to gain more credibility.......but this is a sign of moisture coming up through the slab and is not a real serious problem if you keep it to a minimum, ie, weep holes in bricks not obstructed by garden beds etc...no moisture lying against the house such as water pooling...strange thought that living in Melbourne these days but it has happened lately. The cause is probably damage to the vapour barrier (the black plastic sheet that the slab is poured into) not being pulled up and folded under the first course of bricks by your brickies...if you are not on a slab and don't have brick walls then you have a serious problem.... The crystals are from the concrete leaching out in the drying process. If your carpet was not rotting from this then you are probably okay. Cheers Eric.

Any sort of damp is a problem if you are laying tiles. I assume you want these to adhere to the floor and not just lay there!

Ardex make a range of products for waterproofing the slab.

You will find all the info you need at www.vibro.com.au/

They also make the adhesive too which you should use as you know they are compatible. Get their advice first and you shouldn't have a worry.

Col.

depends on where its comming from
from under the slab...or from sides????
you will have problems if its from under
you can fix from sides ....but it will cost...how bad is the dictator

i have parquetry ....and i live with it...from the sides .....%^&*ing builders !!!!if only i had known what to look for

Sorry this is late but just going back on post and reading on my return. While there is a number of causes and some have been mentioned also to consider are there any pipes in the walls or in the ceiling that may have cracked ever so slightly and allowing a very very slow drip which will also cause this. Is there a tap outside and the pipe runs under your path which may also have cracked causing water to rise over time (rising damp) You can get people to detect leaks in pipes as they do it for pool pipes. Not sure what sort of roof you have but you may have a leak somewhere here during rain (i'd like to see that) as well running down and pooling underslab. Poor path placement with fall running towards the house? Weep holes not clean?

Before you lay any tiles need to find the source of the problem other wise you will only delay the fix.

Brian