very bad survey on old house

happypie

FreeBear wrote: »

Polystyrene is not toxic in itself. It is however, very easy to set on fire, and gives off toxic fumes when burning. It also leaches the plastiser out of PVC insulated cables which poses another safety issue.

A bit of advice for the OP - Please think carefully about slapping cement, gypsum plaster, and other modern materials on to the fabric of 100+ year old buildings. If you use appropriate materials in the renovation/refurbishment (i.e. lime mortar & plaster), you will suffer far fewer problems in the long term.

thank you so much for advice.

did you mean it on internal or external side?

my builder who is going to start work was saying he'll use multi finish.
after reading your comment i googled about both gypsum (multi finish) and lime plaster and lime one is breathable.

in this video - https://www.youtube.com/watch?v=iZlqzASDN_U
the guy says that internal side you can go with gypsum as it probably would be costly to remove everything up to bricks level and replaster.

for now i am only planning to get plaster done internally (after removing polystyrene material). external render may be in future - no urgency on that.

FreeBear

happypie wrote: »

did you mean it on internal or external side?

my builder who is going to start work was saying he'll use multi finish.
after reading your comment i googled about both gypsum (multi finish) and lime plaster and lime one is breathable.

Use lime both on the interior and exterior of the building. If the polystyrene tiles have been stuck over the top of lime plaster, just scrape them off. Give the walls a good scrub to remove any adhesive, and then skim. I'd use a plaster mixed from lime putty and finely ground chalk, limestone, or marble. Alternatively, ready mixed plaster from Mike Wye or fibrechalk from Anglia Lime. Both are just as easy to work with as gypsum with the added advantage of never going off in the bucket.

Got tubs of plaster here that were mixed up 6-12 months ago, and once given a quick stir, are still good to use. Added a bit of pigment to one tub, and I don't have to paint the walls ever again