Blown chimney rendering

[R0L0]

Ok brill thanks bud, was thinking nearly the same thing The top coarses is the worst where the old render was blown and crumbling. And the bottom half is not bad, quite solid.
What is ex metal?

 

[roy c]

It is expanding metal that comes in sheets (either galvanised or stainless) once your pointing has gone off you can attach the ex-met with galvanised nails, shape the mesh so it fits around your chimney (you can fold it to the shape of your chimney then take it off the chimney and fold the edges in so it hugs the chimney when you put it back on )I would do it in two halves and make sure you over lap the two pieces by about 8-12 inches when you fix it to the chimney. The trick with ex-met is when you nail it always work from the middle out and try to get it "tight" as you nail it .Nail about every 6 to 8 inches...use bigger nails if you cant get a fixing ....Scutting is mixing your sand cement and sbr up to a slurry and throwing (Scutting) it on your ex-met with a dashing towel and get a bit of force behind it to cover the mesh .It's all in the wrist action it should make a splatting sound when it hits the wall. After you have "scutted" it let it go off for a while (It wont take long on the brickwork you can wet the brickwork down lightly first!!)then just take off the "High points with a batten or a trowel and leave it to go off before you scratch it.....
"Scutting" is a regional term ad may be called something else in different regions. I was taught how to do it by an Irish plasterer and thats what he called it so thats what I call it. Be interesting to here of regional variations....

 

[R0L0]

Aha expanding metal, yes I sort of know about this, as have watched my grandad put it on a wall for repair. And he used to say put some "slop" on it, which I guess is the same as scutting .
I think he sometimes used chicken wire, would this be suitable if it was thick/strong enough?

 

[roy c]

Horses for coarses,use the proper materials for a proper job !!!

 

[R0L0]

True, was a long time ago when I saw him do it, so probably was expandable metal
Thanks again

 

[R0L0]

I have applied the scratch coat, (scutting worked nicely) and has been on for less than 18hrs now and understand its best to leave for 24-48hrs before the top coat applied. So was planning to leave til mon, but now bad cold weather is forecast from sun with frost and minus conditions. So would it be best to apply top coat today or leave til, bad weather is over? Don't want the cold weather to f*** things up for me
As always help appreciated.

 

[roy c]

If it is all scratched leave it till we get some gauranteed fine weather. It's not going anywhere

 

[joe-90]

Remember to show us some pics when it's done.

 

[R0L0]

Ok thanks will leave it then, on plus side looks like I got a day off
And will put up some pics up when it's done

 

[R0L0]

Just wondered if you have to cap the pots, & could you put some sort of vent on the stack within the loft to allow it to breathe? Say if you wanted to get rid of the pots and completely Flaunch over top?
On another note near completion of the chimney feel like its taking ages as this bad weather slows everything down

 

[roy c]

I would do both, make sure you have vents in any fire-place's that are bricked up and pots vented you get a better airflow and it should stop any damp forming further up your chimney...As for the weather it's one of those things that can't be controlled and last year was the worst year I can remember in over 30 years in the building trade for working outside!!!! It's a case of trying to get inside work so the weather doesn't effect you,

 

[R0L0]

Ok thanks Roy c The rendering has been on for under a week now, and wanted to ask whether I should still cover it to protect from frost or will it be fine? It's a little bit damp from the rain but firm.
Thanks again.

 

[joe-90]

Vents top and bottom usually CAUSE condensation.

 

[R0L0]

I guess you've had enough of my questions
Joe 90 how come? Is it cause it drags in moisture?

 

[joe-90]

Slow airflow allows air in the chimney to reach 'dew point' which then condenses on the inside of the chimney. You need fast airflow - or no airflow - not a bit of airflow.