Slow drying new plaster plus salt deposits?

[substrate]

Hello all,

I really need some advice. We've recently had our bedroom wall replastered after it was ruined by damp coming in from the roof. We had the guttering redone and, after waiting to make sure the plaster didn't get any worse, we had someone come in to strip it back and re-render and skim the area. The wall is internal, next to the window, so only the edge of it is exposed to the outside of the house.

It's been on for just over a week now, and about 2/3 of the area is still not dry, with the skim firm but moist to the touch. This morning, I also noticed a salty deposit had formed in some parts at the edge of the still-wet area.

We called the plasterer; he doesn't know what the salty deposit is. I gather from reading here that it's effloresence. He thinks it needs more time to dry out; I'm concerned that the underlying problem is not sorted out.

To further complicate matters, there is a pipe of some kind that protrudes about 2cm out from the the middle of the wall; we never knew what this was, but our plasterer thinks it may have been a disused gas pipe. I'm more inclined to think that it's a water pipe, and perhaps it's not been capped off correctly.

Any thoughts on what the problem could be, and how to sort it?

Some images :
http://i47.photobucket.com/albums/f181/intolerator/DSC00007.jpg
http://i47.photobucket.com/albums/f181/intolerator/DSC00008.jpg
http://i47.photobucket.com/albums/f181/intolerator/DSC00009.jpg

Thanks

 

[roy c]

What did your "plasterer " use as a backing coat for the Skim coat? Was it sand and cement or a light weight backing plaster like Bonding?. Did you cure the outside damp problem and have all the plaster hacked off and left for a while till the room dried out or used a dehumidifier on it to get the water out of the walls?

 

[roy c]

Posted twice

 

[substrate]

What did your "plasterer " use as a backing coat for the Skim coat? Was it sand and cement or a light weight backing plaster like Bonding?. Did you cure the outside damp problem and have all the plaster hacked off and left for a while till the room dried out or used a dehumidifier on it to get the water out of the walls?

He offered us two options, the cheaper of which was bonding; the more expensive option, which we went for, was sand and cement mixed with a waterproof silicone resin (if I recall correctly). As far as we can tell the outside damp problem is cured, but now I don't know. The original plaster was removed but the plasterer re-rendered it the same day, leaving it to dry for one day before applying the skim. No dehumidifier was used.

 

[roy c]

In my opinion there was not enough time for the wall to dry out ,and "The cheap option" should never even have been suggested. If he offered you that option and didn't know what caused or what the "salts "were then he wasn't very clued up. You can either have the whole lot knocked off and get a dehumidifier in and dry the walls out or if you are sure the damp problem has been cured you can still get the dehumidifier and pull the water out of the walls and dust off the salts. Usually a wall that has been treated for damp will take a long time before the salts stop coming thru, but you can brush them off every now and again till they stop. Most of the work I do or have done is on stone walls that can be up to 16" to "20" thick, and they take along time to dry out ....so it's not recommended to paper them but if needs must they can have a few coats of emulsion on them (Not vinyl silk) use matt...But dehumidifiers work wonders....Good Luck.... I must stress that before you paint the walls you must leave them for at least 3 weeks. There are special admix's that are used for work carried out on damp walls these allow the water in the walls to evaporate out thru the render mixes and also there are certain plasters that are used inconjunction with these admixes.. I used to be a Sovereign agent and did a lot of dry-rot ,woodworm treatment, tanking systems, and DPC injection work all followed by the remedial work that was needed after these systems were used. I also then ( thru Sovereign) gave 30 years gaurantee's on all my work. It is not just a case of knocking off damp plaster and scratch-coating, floating out and skimming ,job done. Like anything that is going to work there has to be a system to follow, this doesn't come cheap but when it is done like this the customer can or should rest assured that there are no "come-backs" and if there are then they will be put right free of charge..I dont do this work too often now and am a bit rusty on some of the chemical names of products but there will be "Specialists" in your area that you can always call in for free advice and surveys..... Hope this helps you understand a little better about your problem .....

 

[joe-90]

A week is nothing. After floods the walls take up to six months to dry out.

Forget it for a few weeks. Why didn't he pull the redundant pipe out instead of plastering around it?

 

[substrate]

A week is nothing. After floods the walls take up to six months to dry out.

Forget it for a few weeks. Why didn't he pull the redundant pipe out instead of plastering around it?

He was convinced it was a gas pipe and that we'd need a gas engineer to sort it out; not something we had time to do.

 

[trowelmonkey1]

best to be safe, if you don't know where the other end of that pipe is the last thing you want to do is open it to the world.

i agree with the posts, the wall probably hasn't had time to dry fully, the salts are coming from either the wall or some 'bad' sand used in the render, either way they should stop of their own accored...EVENTUALLY, just keep brushing them off, get a de-humidifier in to speed up the process, once dry and the salt stops if the plaster is still ok then bobs your uncle.

should have been told to leave the wall to dry fully though first, there is special post-damp plaster called dri-coat which could have been an option also but that's by-the-by now.