Box Lintel

[rustyross]

Hi guys.

I am currently going through a full refurbishment of a 100+yr old, 9" thick solid walled, farmhouse.
I am currently doing all the work myself to keep our budget under control & I would like to install a set of 3 Pane Bi-fold doors. There is set of patio doors already installed & I will be increasing the size of the hole to accommodate the bi-folds, this will obviously require the installation of the new lintel & here-in lies my question;
My plan is a little unorthodox so please bear with me.

I am thinking of installing a standard box lintel on the inner 'half' of the wall now (so I can carry on with other works) then install a second box lintel on the outer 'half' of the wall later on.
I understand this is probably not the conventional way of doing it & would be more expensive (although i am eyeing used/surplus litels) is there any reason why is would not work? Obviously i'm concerned about transfering the loads to the outside edge of the wall while the lintels being installed & the span I will be installing (2100 - 21500mm bi-folds)

As I say the walls are 9" solids with a row of header bricks every 4th row.
There is a single row of bricks above the planned lintel placement, then the joist wall plate & 11 rows before the bottom of the bedroom window above.

Thanks in advance

 

[tony1851]

You are over-thinking the problem; a couple of strongboys will do.

 

[rustyross]

Hi,

No sorry, i'm fairly happy strongboys would support the walls while i work - the double box lintels are above the bi-folds permanently.
I know our local building control is not a fan of T lintel which is why I ruled them out.

 

[tony1851]

Hi,

No sorry, i'm fairly happy strongboys would support the walls while i work - the double box lintels are above the bi-folds permanently.
I know our local building control is not a fan of T lintel which is why I ruled them out.

Why not use an ordinary catnic lintel?? Surely a box lintel is not intended for exterior use?
Your Building Control body cannot unilaterally declare that they don't like such-and-such lintels. As long as the lintel satisfies structural requirements, the council has to accept it.

 

[rustyross]

yes thats my plan - effectively using two 100mm catnic's rather than one 200mm unit.