My 1st Time

[padstar]

I have 3 doorways to open up and lintel over and i am planning on doing the 1st this weekend. Typically it is the most difficult of the 3. Given i have never done this before i am a little nervous so need some help.

The wall is a solid brick wall. There are 2nr 1800x100x140 lintels going in to form a 1500mm opening. I understand the theory of prop, remove bricks, install lintel with 150mm bearing, remove opening.

My concerns/queries are;

1) How many strong boys should i use? I have heard that as it is a solid brick wall, it will probably self support which is great. I wont be leaving it to chance but knowing if that is the case would help with the nerves. How many and where should i install them

2) Do I lay the lintel on a bed and then pack mortar in the top when the base has gone off or should i mortar the top of the lintel offer it up, wedge in place then fill under the lintel after the top has gone off.

3) What mix should i use for the mortar?

4) I have removed a few bricks at either end. Is it now best to use a grinder along the top and bottom mortar joints and pop the rest out? Are hammer and bolster safe to use or will it effect the bricks above

I plan to remove the red dot bricks and lay the lintel on the blue dot bricks. Is there anything else i should be aware of?

 

[plastic_peanut]

I am no expert but there are a number of YouTube videos that can give you some guidance before you begin

 

[noseall]

1) How many strong boys should i use? I have heard that as it is a solid brick wall, it will probably self support which is great. I wont be leaving it to chance but knowing if that is the case would help with the nerves. How many and where should i install them

2) Do I lay the lintel on a bed and then pack mortar in the top when the base has gone off or should i mortar the top of the lintel offer it up, wedge in place then fill under the lintel after the top has gone off.

3) What mix should i use for the mortar?

4) I have removed a few bricks at either end. Is it now best to use a grinder along the top and bottom mortar joints and pop the rest out? Are hammer and bolster safe to use or will it effect the bricks above

Two strongboys will be plenty, but I'll be surprised if you even need those as long as you attempt one leaf at a time.

We also have another pair of acrows handy to push the lintel up into place along with a bed of squeezed mortar on top of the lintel. We then fill underneath with mortar and then remove the acrows.

This opening we did without acrows...

Untitled

• noseall
• 12 Jun 2015
• 1

Untitled

• noseall
• 12 Jun 2015
• 1

Untitled

• noseall
• 12 Jun 2015
• 1

Untitled

• noseall
• 12 Jun 2015
• 1

 

[cdbe]

I've found my car jack has been quite useful in situations like this where, if you have something solid below, it's great for pushing up to existing masonry. I've used it for my steels and to push up a big padstone:

If you don't have one, get a finger trowel which will allow you to push the mortar into any deep, thin gaps:

I know the conventional wisdom is to pack the gap between the lintel and the brick it sits on with slate or similar but unless it is uniform you might struggle to get it tight and not wobbling - I prefer to use a firm mortar bed that I can pack really tightly with my finger trowel. 4-1 will be fine, as dry a wet mix as you can get to minimise shrinkage.

I'd probably needle that rather than strongboys but that's because I have a nice little 4 foot long mini RSJ that would do both skins at once and give me more room to work.

 

[padstar]

Thanks everyone. I have watched a number of tutorials just nervous about a wall falling on top of me as i have not done it before.. The theory i understand

I cant access the inner leaf from inside the house without a lot of disruption so was planning on installing both from outside 1 on Saturday and the 2nd on Sunday. Is that enough time to let the mortar go off before removing the prop?

I am thinking to prop the outer leaf with acrows, slide the 1st lintel in. Load the top of it with mortar get it roughly in place then raise up using 2 strong boys to squeeze the joint and point. Then fill under the lintel using the finger trowel and leave until the following day before removing the strong boys then repeat on the outer leaf.

How much of a mortar joint should be left between the lintel and bricks 10-15 (i need to lose 25mm over the 2 joints)?

 

[23vc]

If these were big steels supporting more than the triangle of bricks above, 1 day wouldn’t be long enough to leave the mortar to set. For this, you may get away with it. Might want to dry pack it instead or wait longer

 

[23vc]

How much of a mortar joint should be left between the lintel and bricks 10-15 (i need to lose 25mm over the 2 joints)?

could go down to nothing

 

[padstar]

could go down to nothing

Is it best to have no joint or is a mortar joint ok or does it not matter as long as it has set before removing the props

 

[padstar]

If these were big steels supporting more than the triangle of bricks above, 1 day wouldn’t be long enough to leave the mortar to set. For this, you may get away with it. Might want to dry pack it instead or wait longer

It will be supporting the external wall upstairs in the house over a 1500mm span. I think i will leave the props in place for a few days before doing the 2nd just in case.

 

[padstar]

It was all going so well then i found myself in the road cursing myself for being a fool!.

Brickwork removed and nicely propped up with 3 strong boys (it seemed fairly sound as i was removing the bricks) then as i was starting to feel slightly chuffed at my work especially as i had opened up a nice 200mm hole within the internal load bearing wall to the right so i no longer need to leave a visable nib for it to sit on, i discovered the stair/upstairs landing joist trimmer sat on the inner skin!. Not going to work with my concrete lintel i guess. School boy error.

What is the best way to deal with this? Install one of these 150mmx90mmx24 mild steel channel into the internal skin and cut the trimmer into it then install the concrete lintel externally? The open span will be up to 2m.

Really annoying as i was looking forward to having this well under way this weekend.

 

[23vc]

So the trimmer is mid-span of your new opening? If so, potentially timber lintel for inner skin? What’s the trimmer supporting, the landing floor joists?

 

[padstar]

Yes mid span. The trimmer supports the joists as shown in the image below plus the upper level of external brickwork.

 

[cdbe]

Hang a joist hanger off the lintel.

 

[padstar]

Can the entire landing be held from 1 joist hanger?

 

[cdbe]

Yes. A heavy-duty one, not one of those thin bendy things.