I am after some advice in terms of what is standard practice regarding specifying lintels.
BC are involved, I’d just like some constructive input from you guys on the forum before talking to them.
I am building a 2 storey extension, and I have 2 windows in the ground floor wall. The windows are 1250 wide and are in the wall that is perpendicular to the floor joists. The Building Inspector has said that he is OK with the joists being built into the wall, so that is what I will be doing.
Construction is Brick outer skin, thermalite block inner, Plasterboard/skim finish.
First question – Concrete or steel?
If I use concrete, is it a case of putting one lintel in each skin, and a cavity tray above?
Second question – Loading
The loading of the outer wall is pretty straightforward. It is a gable end wall, that goes up another 5m or so.
However loading of the inner wall will include the load from the floor joists, and the board/skim finish.
If I use concrete, would I use a thicker one on the inside than on the outside ? (They only come in 2 thicknesses don’t they)
If I used a standard steel lintel one, then run one course of blocks, would I be OK sitting the joists on top of that course? Or should I be looking at a heavy duty lintel that extends over the top of that course of blocks as well, so that the joists actually sit in the top of the lintel.
The concrete route seems to be significantly cheaper than going with steel ones, and the rest of the house has got concrete lintels visible painted white, so cosmetically it isn’t really a problem.
Concrete
65 x 100 x 1800 for outer
140 x 100 x 1800 for inner
= £30 ish
Standard Steel (Catnic CG90/100 type) 1650mm = £60 ish
Heavy Duty Steel (Catnic CZ90/100 type) 1650mm = £95 ish
Any advice or tips will be gladly received.
Cheers
BC are involved, I’d just like some constructive input from you guys on the forum before talking to them.
I am building a 2 storey extension, and I have 2 windows in the ground floor wall. The windows are 1250 wide and are in the wall that is perpendicular to the floor joists. The Building Inspector has said that he is OK with the joists being built into the wall, so that is what I will be doing.
Construction is Brick outer skin, thermalite block inner, Plasterboard/skim finish.
First question – Concrete or steel?
If I use concrete, is it a case of putting one lintel in each skin, and a cavity tray above?
Second question – Loading
The loading of the outer wall is pretty straightforward. It is a gable end wall, that goes up another 5m or so.
However loading of the inner wall will include the load from the floor joists, and the board/skim finish.
If I use concrete, would I use a thicker one on the inside than on the outside ? (They only come in 2 thicknesses don’t they)
If I used a standard steel lintel one, then run one course of blocks, would I be OK sitting the joists on top of that course? Or should I be looking at a heavy duty lintel that extends over the top of that course of blocks as well, so that the joists actually sit in the top of the lintel.
The concrete route seems to be significantly cheaper than going with steel ones, and the rest of the house has got concrete lintels visible painted white, so cosmetically it isn’t really a problem.
Concrete
65 x 100 x 1800 for outer
140 x 100 x 1800 for inner
= £30 ish
Standard Steel (Catnic CG90/100 type) 1650mm = £60 ish
Heavy Duty Steel (Catnic CZ90/100 type) 1650mm = £95 ish
Any advice or tips will be gladly received.
Cheers