What type of lintel please?

[brianivor]

I am planning to have a doorway cut through from my hallway into the back half of a semi-integral garage which I intend to use for storage.

The wall in question is 9 inches thick, 2 thicknesses of brick with no cavity ( being an internal wall)

The wall is load bearing, supporting the upper story floor beams and, via a 4 1/2 inch upstairs wall, the roof of what I would say is a conventional 1960s 3 bedroom semi.

A builder has quoted (estimated) for the job in vague terms such as "a suitable lintel will be fitted"

I am aware that the door will need to be a self closing, half hour fire door, but for the door to fit in the wall space available it will need to be as narrow as practicable, i.e. 600 mm wide.

The point of this submission is that, even with this door width, extending the lintel by the recommended 150mm either side of the wall cutout will mean that one end will foul the vertical light switch conduit by about 30mm and I would prefer not to have the extra expense of moving this if possible.

So, finally, my question is - would the "suitable" lintel have to be 9 inches wide (deep?), the same as the wall thickness, or would it be sufficiently narrow to "tuck" behind the conduit which appears to be set into the wall to a depth of about 35 mm?

In summary then - could you advise me on a "suitable" lintel (size and material) for this project?

Thank you in advance to all those kind enough to reply.

 

[noseall]

Use a pair of pre-cast concrete (pcc) builders lintels - 70 x 100mm and modify the conduit, i.e. use cable and capping.

600mm wide doorway? This is prohibitively narrow and will restrict what you can pass through such an opening. I'm not even sure you can buy a fire door this size.

 

[brianivor]

What is cable and capping please?

 

[noseall]

What is cable and capping please?

Capping, (metal or plastic) is a more discreet way of dealing with cables buried beneath plaster. Trunking or conduit is bulky, hence the need to partially sink it into the masonry and subsequently interfere with the lintel bearing arrangement.

 

[brianivor]

Thank you Noseall.

Am I right in assuming then that the lintel will not be flush with the front surface of the 9 inch brick supporting wall - and that the switch cable can be run in front of the lintel and still be covered by the finishing plaster?

 

[seasickstevie]

I can't see why the conduit should be in the way.
Your two 100mm PCCs side by side will only add up to 8", and your existing wall is 9".
Slide them in from the other side.

Or am I reading this wrong?

Come to that, if the switch cable is PVC double-insulated and in good condition, you could dispense with the conduit, and plaster over the cable.
(Although I'd prefer to see it in 16mm oval Egatube (plastic conduit))

 

[brianivor]

Thank you,

My concern about disturbing the existing conduit was that, if in the future the house was rewired, the existing cable could be drawn easily out of the conduit from above. However, what you say makes sense.

Regarding an earlier comment about the 600mm width fire door, the garage was only to be used as a store/utility room and a freezer will go through a 600 mm door.

 

[noseall]

a freezer will go through a 600 mm door.

Only if you take it off its hinges.