help with rendering (blocking up old doorway)

[oasis]

iv got a job on and part of it involves bricking up a door way, from the inside its a easy dab or bonding job but on the out side it will need rendering,the old render is quite a flat finish,just old crappy paint, but whats the best way to go about rendering it.

Will it crack on the joint lines if i make it flush? or should i set the bricks back a bit and make the door way shape stay by say 2"-3" ? or is it ok to bring flush with the rest of the wall?
any help would be good taaaaaaaaaaaaaaaaa

 

[rockhardsolidplastering]

leave it about 10mm back and use strong mix bonding agent and using tool brush brush agent along edge of existing shouldnt crack

 

[essexandy]

Cut existing render back from joint then paper and wire over the joint and render as normal.

 

[Chris W]

bit of a tip, in my experience concrete 7n blocks will serve you better than bricks or 4n celcon/durox type blocks..

 

[oasis]

thank you people, i guess if i can i should ask if we can just set it back a few inches and keep the shape to the old door. easy to render then and not to much chance of a crack? or am i beein lazy?

 

[Chris W]

not a few inches mate, bout 10mm..
see church on 'rendering thickness..'

 

[essexandy]

thank you people, i guess if i can i should ask if we can just set it back a few inches and keep the shape to the old door. easy to render then and not to much chance of a crack? or am i beein lazy?

Yes

 

[Chris W]

Cut existing render back from joint then paper and wire over the joint and render as normal.

whats the paper for andy?
i get the eml over the joint but are you on about building paper underneath? if so what for? wouldnt that eliminate any suction at that point?

oasis, its not hard to bolster off 6" either side of the doorway and stick some eml up the joint mate, just get a roll of 4" from the merchants, bout a fiver..

 

[spunky]

i had a similar job with single skin selcon block ........isnt this a bit wrong?

 

[Chris W]

people love em to brick up with cos you can cut em with a handsaw but i dont like em to render on... i dont think theres anything against building regs with using celcons externally though..

 

[spunky]

but single skin seggs they soak up water like a sponge ???

 

[Chris W]

wouldnt matter if they were concretes on a single skin mate, wants something to stop damp like a cavity or studding off and a vapour barrier/cellotex engineerings would help but theres the mortar joint isnt there...

 

[oasis]

ill just let um no were gana have to take the hole back end off back to brick then re render that should blend it back in all good.

 

[spunky]

i cant get my head around we build twin skinned houses with a cavity but when someone takes a door out we put the worse type of block in for absorbing water on the outside of the house and its alright ???........with no cavity ???

 

[essexandy]

whats the paper for andy?
i get the eml over the joint but are you on about building paper underneath? if so what for? wouldnt that eliminate any suction at that point?

oasis, its not hard to bolster off 6" either side of the doorway and stick some eml up the joint mate, just get a roll of 4" from the merchants, bout a fiver..

[/quote]
EML doesn't always stop a crack forming if you paper over the joint (building paper) and wire over that if the joint cracks it does so behind the paper and rarely comes through onto the render (only with very severe movement). I'd use a sheet of EML I prefer it to the roll stuff for this type of job.

 

[Chris W]

i cant get my head around we build twin skinned houses with a cavity but when someone takes a door out we put the worse type of block in for absorbing water on the outside of the house and its alright ???........with no cavity ???

thats just it mate, its not alright at all.. cavities are there for 2 reasons, to form a barrier to stop water penetration and to contain insulation( which is why cavities are getting bigger everyyear - to bring us in line with the kyoto agreement (document L))
without a water break of some kind, unless the substrate is completely waterproof (tanked) then there will always be water ingress...
thats when studding off with treated timber and adding cellotex for insulation and a vapour barrier comes in..

 

[oasis]

ok ill use solid blocks then thero seal them then render them ha

 

[spunky]

the job i had was patched spar outside and do the inside which i thought i would do with limelight backing coat and fininsh plaster cause i thought they might be porous ............then thanks to this lovely site its not............ luckily the builder did the inside with hardwall anyway ......if i ever come across it again could i use two coats of sbr slurry and go over the existing so hopefully the moisture will go back into the cavity through the sides of the block or am i a drunkard loser ;D

 

[warriorupnorth]

Yep

 

[oasis]

ur not a drunken losser mate,just a funky spunky monkey

 

[warriorupnorth]

christ what a long drawn out thread for a bit of an old door ole , just block the twaat up and render it for christ sake

 

[spunky]

paul trust me theres alot of small children in yezmen southern ukraine who's lives depend on this thread .........trust me mate live for the people .....give them a chance ............its all we ask ..............please mate .........

 

[warriorupnorth]

Ok

 

[lucius]

Aglite or similar agregate block is best for rendering on.
Lucius