Connecting timber lintel to brickwork wall

[SillyBilly]

I am building a 150mm timber frame annexe extension attached  to a flat roof single storey brick wing of my house.  My original intension was to connect a 3-ply 150mm wood lintel over the new rear door using a metal joist hanger in the existing brick wall.  I have since been advised that standard joist hangers need 9 courses of masonry above them and my first floor will be of timber!  
I could use a  Strongtie SafetyFastWeldedMasonry Restraint hanger SFWHI184/135/100 which come with a restraint strap and doesn’t need masonry above it.  This particular hanger is for 3x45 I-joists: the other range of Strongtie SFW doesn’t include that 3x45 width.

If I go down this route I will have to cut out one course of the brick to get the overhang lip onto the wall.
The alternative is to cut a hole for the 3-ply lintel but this is close to the end of the wall and would need restraining.
Comments welcomed.

 

Edited November 5, 2021 by SillyBilly

[Gus Potter]

Hello Sillybilly.

 

If you can post a sketch drawing and maybe a photo you may get some good pointers.

 

 

[tonyshouse]

Cut a pocket 

[Temp]

5 hours ago, SillyBilly said:

My original intension was to connect a 3-ply 150mm wood lintel over the new rear door using a metal joist hanger in the existing brick wall.  I have since been advised that standard joist hangers need 9 courses of masonry above them and my first floor will be of timber

 

I think cutting a pocket for it to sit in is the correct method but..

 

You can get joist hangers with long tails that can be wrapped over the top of a beam and fixed to the other side. Have used these to fix joists to an UB. In that case the web was filled in with timber and these long tails were wrapped over the top and nailed to both sides. Only have chipboard floor on top of the beam not 9 courses of bricks.  

Edited November 5, 2021 by Temp

[Gus Potter]

Hi Temp.

 

Just to take a step back.

 

When you are doing the panel drawings for a joiner to work to for a timber frame you look at what off cuts you are going to generate. Now a standard length of timber is 4.8m and you can end up with say a few handy offcuts that you can use. Now although you may have a 3 ply 150 "lintel" on paper it may be that it is not carrying any significant load.

 

If you you are using 145mm studs for the walls then this is an easy way of using the offcuts to build out the thickness of the wall over a doorway / window. The actual width of a C16 timber is 45mm so 3*45 gives 135mm, often the OSB board on the kit is 9.0 or 11.0mm so the joiner just needs to put a ripping on the inside of the lintel and this allows the plaster board to plane through with the 145mm studs ( we cut ourselves a bit of slack on 1.0mm). It's the simple stupid approach but economic practical design.

 

If the 3 ply lintel is carrying some load then rather than trying to find a hanger then you can often support the end of the lintel using a couple of vertical studs and these you fix to the wall.

 

Have a look to see what your 3 ply timbers are doing and look for the simple easy options?

 

 

[SillyBilly]

13 hours ago, Gus Potter said:

If you can post a sketch drawing and maybe a photo you may get some good pointers.

The first pic shows the actual size and position of the 3-ply wood lintel; the second shows the 900mm gap btween the framing and wall.  The framing has  the load of the I-joists which run parallel to the wall and the upstairs framing. The bottom of the wood fascia is at the level of the top of the brickwork.

[SillyBilly]

Thanks Gus.  The loading is from 2 I-beams running at right angles to the 90cm lintel, chipboard flooring and the upstairs framing etc.  On the right of the 3-ply there is a pillar of resin-glued and screwed 145 x45 as pic.

 

 

 

 

 

I would have preferred to have used two studs on the left of the doorway but the waste pipe to the extension would have clashed

[Gus Potter]

Evening SillyBilly.

 

To get you moving I would explore further cutting a pocket for the 3 x 145 lintels so they rest fully on the brick 102.5 mm. Wrap the ends of the timbers with DPC to keep them dry. I'm not sure how to interpret your plan view sketch but by the sound of it the loads the lintel are carrying are not too high.. thus you probably don't need a pad stone under these particular lintels as these bricks have a descent compressive strength and the mortar looks faily sound... the timber with the grain orientated horizontally will crush before the brick.

 

When you get a chance just check with your designer that it is ok to do this.

3 hours ago, SillyBilly said:

I would have preferred to have used two studs on the left of the doorway but the waste pipe to the extension would have clashed

The two studs to the left of the doorway can come in handy and sometimes they have a structural intent...they may also be helping to restrain the masonry / carry vertical load and also as you may expect act as a sub frame for the door. You''ll probably be strapping out what was the existing outer leaf of the wall and adding a bit of insulation too.

 

If you have transferred the vertical load to the masonry then you can maybe add studs if lateral restraint to the masonry is required and these may be able to be arranged to work around the drainage.

 

The main thing is that by pocketing the lintel you are probably doing no harm and this will let you crack on while you check with your designer etc. Just be sensible.. clearly if you are going to knock holes in the masonry for doorways near the lintel support then it may not be enough to hold up the extension during the construction.. let common sense prevail!

 

All the best with the project.

 

 

[SillyBilly]

Thanks

 

[SillyBilly]

I can see a problem using the pocket approach as I did  the framing before the problem arose.  I wont easily be able to get the timber lintel  into the pocket!

The hanger approach doesn't have that problem.  Unfortunately the Simpson Strongtie SFHWI184/135/100 SafetyFastMasonry  restraint hanger is not a stock item and I have been quoted £94.69 for  one. 

If I do use a pocket I can surround it with dpc.  I presume I would use my mortar gun to fill around the fitted lintel and some sort of silicone to make it air-tight.  Do I just add 10mm  at each edge?