cavitl wall lintle

[stevie-b]

hi all, i am opening an external cavity wall to place french doors.

I was going to use a catnic but the cavity is 40mm and i cant find one to fit a 40mm cavity

any suggestions.

door is 1200mm

 

[stuart45]

Use one for a 50mm cavity. Cavities often vary slightly in size. You can adjust the position to suit. !0mm isn't a problem.

 

[ChapiTheBricky]

double check that the upstand in the middle of the lintel is less that your cavity size if you're using a catnic or it won't fit. unless the outside wall is facing brick i wouldn't bother using a catnic and just use two type c concrete lintels. if you need further explanation give me a shout.

 

[stevie-b]

thanks for the input.
how can a catnic with a 50mm upstand fit in a 40mm cavity??

the walls are both brick. The external wall would probably look a bit naff with a concrete lintle.

can i use 4" angle iron?

 

[stuart45]

thanks for the input.
how can a catnic with a 50mm upstand fit in a 40mm cavity??quote]

Cut 10mm off the back of the bottom course of bricks with an angle grinder if you need to.

 

[ChapiTheBricky]

angle iron's fine, catnic might actually be your best bet for ease of intallation though, providing you get one the right size. Remember there are other manufacuters of these type of lintel apart from catnic. You may also be able to use a type of lintel that catnic use designed for timber frame construction which is held against the internal skin with little clips every 600mm, i have never seen or done this but see no reason why it wouldn't work. Remember your dpc apron and weepers too.

 

[stuart45]

Stevie,
Another option is to look on e-bay for one of the older catnics where the inside skin sat on top of the upstand. You wouldn't have to cut the bricks with one of these.