Advice please!!

euphoria

I am in the middle of renovating and extending an old cottage. In the coming weeks my contractor will be stripping all the plaster and the stone underneath will be revealed. My intention is to have it sandblasted and pointed. However i have also thought about having it replastered with the "old cottage effect" (This effect is made up of blobs of sand and cement that starts at ground level and works upward)

My concern is that in time, although it will be insulated slab 50mm, that dampness will make its way through.

I would be grateful for thoughts/advice/comment/experiences

Thanks

ronaldo84

i take it your on about external walls?? if so i would strip back the plaster and point all the joints and replaster to seal it and then i would build a stud wall (timber or metal) inside this then insulate and plasterboard it. if its a internal wall u could prob point and replaster. i would not recommend fixing a 50mm slab onto a stone wall

euphoria

Thanks for your repy. A timber stud wall has been built internally and my understanding from my contractor is that 50mm insulated slab will be fixed on to the stud.

The exterior wall will have the plaster stripped, then pointed and replastered to seal it.

Will there be a certain amount of dampness regardless? and if so after will it end up coming through the insulated slab?

It's a major concern i have at the moment as years down the road i don't want to have to pay to have this problem solved

anyone had the same experience?

RKQ

euphoria wrote: »

Thanks for your repy. A timber stud wall has been built internally and my understanding from my contractor is that 50mm insulated slab will be fixed on to the stud.

Why?
What insulation will be fixed between the studs?

I renovate old stone building - so using sand & cement is not advisable.
Old stone buildings use lime mortar only.

If I was retained by you I'd have given you 2 choices :-
1. Externally insulate the building - especially as you plan to replaster the house .
2. Insulate internally while maintaining a gap between existing walls & new stud. Use airtight membranes & taps to limit draughts.

If you insulate externally then all the stone walls could be exposed if desired.

euphoria

xtratherm insulation is been fixed between the stud and then 50mm insulated against/on the stud.

there is a gap between existing wall and the new stud.

In the next couple of weeks, the plaster will be stripped off the external walls to reveal the stone. If the quality of the stone is good i plan to leave it exposed.

would i be correct to assume that these would be the next steps?

remove mortar between stone (2 inches deep)
Sandblast stone
replaster between joints
seal joints

Mellor

euphoria wrote: »

This effect is made up of blobs of sand and cement that starts at ground level and works upward

My concern is that in time, although it will be insulated slab 50mm, that dampness will make its way through.

RKQ wrote: »

I renovate old stone building - so using sand & cement is not advisable.
Old stone buildings use lime mortar only.

I jsut want to reinforce this point further as you may not have noticed.
I totally agree with RKQ. DON'T USE SAND AND CEMENT

RKQ

euphoria wrote: »

would i be correct to assume that these would be the next steps?

remove mortar between stone (2 inches deep)
Sandblast stone
replaster between joints
seal joints

Sandblasting the stone will remove all loose lime mortar.
A wirebrush or timber batter with a nail, can be used to check all loose mortar was removed. Mask all windows during sandblasting, as sand will scratch glass & remove all loose or rotten wood on window frames or soffit etc.
Repoint as necessary with traditional Lime mortar.

beyondpassive

Theres an off the shelf drylining system which incorporates, fixing rails, vapour control layer and mineral wool, with thermally broken fixings, which is appropriate for renovation. PM me for details.