Rebuild top of chimney

[stuart45]

If you want to ventilate it you can drill a hole 15mm each side below the plate at 45% angle so rain can't get down the flue. Only if you think there may be a damp issue.

 

[23vc]

thanks, I am also thinking if the plate is only 1 course above the dpc then is there any point in having the dpc
As said before the dpc worries me because it’s a small chimney and worried about it shifting

 

[stuart45]

If it's not a lead tray I wouldn't bother.

 

[23vc]

Cheers. If it’s a lead one are you saying I should use a separate dpc?

 

[stuart45]

The lead tray is the DPC. It stops rain going through the brickwork and down the inside of the brick flue into the house.

 

[23vc]

Got it thanks

 

[23vc]

Another question on this sorry, the mortar mix for the flaunching, I've got a load of plastering sand, not sure if that would be suitable? If not, is a mix of soft+sharp best?
Cheers

 

[lostinthelight]

I mix my flaunching render with more Sbr than water,sbr slurry all pot contact areas ,inside and out and after flaunching wipe the pot joint with brush dipped in sbr, and I use sulphite resisting cement on chimney repairs.It may seem over kill but seeing the damage first hand that tar can do, I like the belt and braces approach
litl

 

[23vc]

Thanks litl can you advise the mix and type of sand? I am sure I heard somewhere that plastering sand is a good choice as its kind of in between soft and sharp sand but I may be wrong on that. Nice job in the pic, gives me something to aim for lol

 

[stuart45]

I like the belt and braces approach
litlView attachment 135136

Nothing wrong with that, especially when working high up.

 

[lostinthelight]

Thanks litl can you advise the mix and type of sand? I am sure I heard somewhere that plastering sand is a good choice as its kind of in between soft and sharp sand but I may be wrong on that. Nice job in the pic, gives me something to aim for lol

I dont know if the sand makes a difference if using Sbr but I use 3.5 plastering sand to 1 Sulfacrete, not to wet to avoid slump, the tacky sbr slurry on brick and pot surface will help the bond. if you use Sbr wash your tools pretty quick
litl

 

[23vc]

Cheers much appreciated

 

[stuart45]

Building sand has more shrinkage and more likely to crack, but is easier to work with.

 

[23vc]

All done, just need to sort the flue out at the top, not perfect but I don’t reckon it’ll be going anywhere and hopefully not leak. Thanks again for the advice

 

[stuart45]

Looks like a really good job you made of that 23vc.