Chimney top concrete flaunching mould repair

Roofing & Guttering Matters Ltd. Business is based in United Kingdom, Halesowen, B63. We service Birmingham and all surrounding areas. www.yourroofingmatters.co.uk - [e-mail] - 07866424178 - 0121 411 9855.
Thanks for watching!
The customer will be having a log burner fitted and they wanted me to make good an old botch job to the top of this chimney. I removed all the old mortar and rebuilt the chimney with a few bricks, made a timber moulding for the new concrete top. Job's a good'un!

[@davesalter]

KZbin tells me 95% of the people who watch my videos haven't subscribed. Be different and subscribe! You know you want to really. lol :)

[@TheToolnut]

I put Sika waterproofer in the mix plus four lengths of 10mm rebar tied in a square a minimum of 50mm inside the formwork. The rebar square is tied to rebar pins driven into the block work at a slight angle. I polybond the top of the block work and put mould oil on the forms, 👍🔨🇮🇪

[@Hew.Jarsol]

Nice drip groove

[@anthonymoore3066]

Is it OK to totally block off a chimney, or does it cause damp thanks

[@davesalter]

Should be vented top and at fire place area really. Or damp condensation will build up in the cavity.

[@AvAGoEro]

Looks a good job. Excellent drip detail. Is there a reason you didn’t line the chimney at the same time as the repair? With the pot coming off it seemed a good opportunity especially if there’s a new log burner going in too

[@davesalter]

Thanks mate. Customer was getting someone else to fit the log burner, i dont do that work. The flue will fit down the pot easily from the top down.

[@liamjohnny335]

Nice mate.. No lime in yrs mixes..to help with expansion etc? Just a question?👍

[@davesalter]

Thanks mate, yeah i have generally only used a little lime when pointing old brickwork, but maybe its something i should look at for the chimney tops also. Do you use it and what mix?

[@sutool1]

Always thought you haunched it upto the line on the pot to give it plenty of depth and fall.

[@davesalter]

I bedded it to match the existing concrete mould, but with about 3.5 inch thick concrete around the base of the pot and with the sides of the pot widening as it goes down that isn't going anywhere.

[@zeez9053]

Nice work 👍🇬🇧

[@deanamends1278]

Good job

[@Toelion]

Banging job bud 🙌🏼✅💚

[@davesalter]

Thanks!

[@topper5421]

A nice neat job.

[@davesalter]

Thanks!

[@zedzed1046]

No sbr, in the mix?

[@davesalter]

No bud, would you recommend it?

[@zedzed1046]

@@davesalter im reasonably new to it myself but it allows for flexibility in the flaunching, it is expensive so if your not using it much it might not be something you can justify buying as it has a life, worth looking into though, all the best.

[@davesalter]

@@zedzed1046 Fair enough, yeah well good old fashioned sand, cement, (ballast if needed) or other support, like i used slate in this video, should be fine i think. If its mixed right and not too much water, which will weaken it once set, then its good to go i believe. I do use a plasticiser in the mix which gives the mix more workability when laying it, adds to strength and improves frost resistance.

[@zedzed1046]

@@davesalter I first encountered it when on a roof, a builder was dropping a stack and rebuilding it, then used the sbr bond to prime the top of the brickwork before setting the pots and flaunching, with it in the mix, there is a whole list of things it does compared to say a normal admix, too many for me to write, google will have the numerous specs.