securing chimney gallow brackets, rawlbolts or thunderbolts

[ash1212002]

All 4 chimney breasts within the property are going to be removed 2 bedroom terraced property

party wall agreement is in place neighbour has no objections

gallow brackets 70 X 70 X 6mm Horizontal angle 300 + 80mm overhang Vertical angle 370mm and 5mm mild steel plate has been ordered

I have been given the option of 2 types of fixings to use either a m10 rawlbolt 25mm projecting 80mm long bolt with resin fix. or thunderbolts m10 either 75mm or 100mm without resin fix

Are there any pros or cons of of which fixings i should go for? your thoughts and recommendations would be appreciated

 

[tony1851]

Are you doing this through Building Control?
Most councils don't like gallows brackets for supporting a chimney stack in the roof.

 

[ash1212002]

My local building control i have spoken to and they are happy with the proposal, the dimensions are

* Left side rear room loft chimney breast 304.8mm deep by 939mm wide
* Right side front room loft chimney breast 304mm deep by 952mm wide

 

[limerockconstruction]

M10 100mm thunderbolts would be my preference.

 

[ash1212002]

i think the thunderbolts are the safer option as i have read on the web there is potential that rawlbolts could crack the brick...