Garage door lintel

[i_am_fubar]

I'm getting a bad feeling about this house, considering the work thats going into just the garage...

The side door (i.e. the one you walk through, not take your car through) has a lintel above it (as all doors in load bearing walls should have). The problem is, the lintel only over laps the door frame on one side. the other side, its only rested on half an inch of brick. Best of all, if I push it, it moves, and the plaster on the outside of the garage (inside of hall way) crumbles off.

The recess for a full sized lintel (half a brick overlap each side) was cut out, but after this shorter lintel was put in, the gaps at each end were filled with morter. On one side, this morter was so loose I removed it, along with a few bits of brick that had broken off.

If for nothing more than peace of mind, I want to replace this lintel with a longer one and re-morter the wall around the door frame.

While I understand the dangers of removing a load bearing piece of structure. There is a gap along the top of it of about 1cm and as I said, it wobbles, so theres no real load being supported anyway.

By load bearing, its only supporting the floor of the room above, which is empty and I can keep it that way.

Are there any regultaions governing replacing of lintel? where can you get them? and is it worth making one out of reinforced concrete?

Cheers, Sam.

 

[simoniris]

If you're confident in your abilities and the aperture is already there then there is nothing to stop you replacing the lintel. When new doorways are formed in existing walls each face of masonry is cut out to insert the lintel anyway so you there is a period where the masonry above is not fully supported.
Phone your local builder's merchant and tell them the opening width and wall construction - and also the aperture height and they will be able to suggest your options - either a PCC lintel which is visible from the outside or a Catnic type steel lintel which has a flange offset to the outside to allow you to infill above with masonry to hide the lintel itself.
You'll need a handful of Akro props to prop the structure as necessary - a decent timber across the width of the door with a prop under each end should allow you to work safely [probably a good idea to take the weight off the floor above the door aswell using the same method] - each skin should be secured together using wall ties anyway and lateral compression will prevent the courses above collapsing - PROVIDED the mortar is in good condition.

 

[i_am_fubar]

Ironically, the bricks above the lintel are jointed with the most sound morter in the room. While I understand the deisre to have a support on the walls while working, there won't be any way to fit jacks in as it'll be old lintel out, new lintel in. And, also, the opening in only a meter across.

I found out yesterday that the guy next door to me is a building servayer. May see if he can come in and have a look.

No problem with visability issues, one side of the wall will be masonry painted, the other side re-plastered.

Will probably look at removing the old lintel tonight, checking the gap, then slotting it back in. As its not supporting anything at the moment anyway, I dont see a problem with doing that.

Is it worth removing the door frame while doing all this?

Also, its still better than the front door, that has no lintel, when the door was replaced for double glazing.... it collapsed. will be looking into that at a future date.

Sam.

 

[simoniris]

There should be one lintel per skin - unusual that there is only one - is it a single skin wall? Again, unusual [read disaster!] if anything other than a single storey shed.
Should get a new lintel which is long enough to get the correct bearing on each side of the aperture - 100 to 150mm ok for door but depends on structure above.
Yes, remove the door frame, will need to jack the lintel once it's in to pack beneath it to get proper support or brickwork above could sag.

 

[i_am_fubar]

Indeed, a single skin wall. it was an extension built around the existing garage. The only load above the wall is a floor and NOT any roof/extra wall loads.... I would pull the ceiling down to get some pics.... but its thought to be asbestos.

 

[simoniris]

Oh dear, it's not your day is it!!
But, simple job, whip the door frame out, get the new lintel in, mortar above lintel, prop it with akro's, pack beneath the ends and point in [slate is good for packing - very strong in compression and thin enough to get accurate packing heights]
Leave props in for 24 hours and then re-fit door frame.

 

[i_am_fubar]

Ok, nice weekend job there...

One last thing. if I made up a timber frame, welded some re-bar together as a skeliton, dropped it in and then filled with concrete, letting it set for a weekend, would that be an adiquit lintel?

Sam.

 

[simoniris]

For the 10 quid a PCC one will cost you I shouldn't bother!
But were a PCC one 500 quid I would still say no. Concrete is strong in compression but not tension. The reason PCC lintels work is that they are pre-stressed, ie formed with a curve. This has been calculated to each lintel section & loading to convert the tension stresses into compression stability, the curve acts like an arch in a bridge, downward forces spread laterally placing the lintel under lateral compression force rather than downward tension. If you make your own it would sag like the brickwork above it.

 

[i_am_fubar]

While I will look into getting a PCC one (portland cement concrete?). I'd be tempted to argue the point of a saggy reinforced concrete beam. However, as a noob, I humbly accept your advice.

 

[simoniris]

With the loadings you have it is unlikely to sag but all the same, PCC is the way to go. Pre-Cast Concrete is the expanded acronym!

 

[i_am_fubar]

... The world is over.... Wikipedia lied to me. I put in PCC, and it came out with portland cement concrete... I'm scared.

(I use wiki a lot if you can't guess)

Sam

 

[simoniris]

Possibly just an americanisation - see general discussion forum note USA!