RSJ vs Lintel on 2.6m External Wall/ Knock Through

[monkeysDIY]

Hi Folks,
Hope all are well?
I am after wisdom on an external wall....
House is 1987 Link-Detached will block inside and brick external walls. Kitchen has a standard door with small wall then window. I wish to remove this wall extend the window and suppport all with a RSJ or Lintel... gap would span 2.6m. What would be difference between the two? Also any ideas on costs or days one/two/three builders I can expect....As always really appreciate assistance....

Untitled

• monkeysDIY
• 16 Sep 2009
• 1

 

[mater]

between the door and window looks about 3m so you would need a 3.5 catnic lintol to do this, would take 2 men about 2 days to complete with plastering, not sure on cost as rates vary all over the country but the lintol would be £200-300

 

[monkeysDIY]

Thanks Mater,
I will be rebricking from the left so I have a 1800 window & 750 door, so added bit for frame. Is there a difference between RSJ & Lintel....costs, strength, installing??? etc etc??? Struggling to get builder to arrive for a quote let lone start the job!!!!

 

[freddiemercurystwin]

Thanks Mater,
I will be rebricking from the left so I have a 1800 window & 750 door, so added bit for frame. Is there a difference between RSJ & Lintel....costs, strength, installing??? etc etc??? Struggling to get builder to arrive for a quote let lone start the job!!!!

A lintel will be far easier as it is designed to support a cavity wall, using an RSJ will be daft as it would sit under the bricks and you'd have to hide it on the outside. Only way to get costs is to get quotes, despite how dificult that may be.

 

[monkeysDIY]

Absolute PITA I tell theeeeee!!!!
I'll get calling on Monday again then.Half tempted just to get it and do it myself...... but if it all goes wrong, it will fall into garden and I'll need that for me tent!!!!
Looked on Catnic site. Funny looking things.... Still Physics is Physics!!

 

[mater]

if you do have a go at it yourself make sure you get the right one for the size of your cavity,they have codes on them so measure your cavity width ,the lintols come in 50mm, 75mm and so on.

 

[monkeysDIY]

Thanks again Mater,
Silly question... whats the easiest/ least mess way to measure it in advance? Should I rip the plaster off at the door top??

 

[monkeysDIY]

OK, no I believe I have spent too much time looking at Lintels..... Am I confusing myself.....
I can see how a "H" Lintel would support when in place, does a standard "Cougar" lintel only work on fresh installs? What style am I needing when knocking through a wall. It is external bricks with block intenal, supporting floor, masonary and roof. Gap I have measured to be 2.7m am think happy over engineer so 3100mm wide.
Failing that.... what/ who do I need... Beam Counter, Structural Engineer, Architect or some one I am yet to find?????

 

[^woody^]

You need a lintel that looks like an upside-down T, and of a width suitable for your cavity size, which will be 50mm from 1987. These tend to be easier to install

If using a Catnic brand, then this will be in the shape of a boot - with a box section internally and a thinner section on the outer edge to hold the external bricks

If using a lintel, its very important to support the centre section during install and untill the bricks you replace have gone off. Otherwise it will bow

If you use an RSJ on the inside, then you need a L shape lintel for the external bricks

 

[hotrod]

Hi monkeysdiy, yes you can use a standard "Cougar" (CG) style lintel for your opening. Like this:-


Something like a CG70/100 or CG90/100 will probably be ok but you need to specify the cavity width and get a lintel to suit. Hopefully Shy will confirm for you or you can contact Catnic.

Where is Shy these days? He gone and gotten himself a new ladyfriend or summat

 

[monkeysDIY]

Tell me about this Shy fella..... New lady fried Huh? Can you find them on here too?????

Anyroad..... bored this morning so attacked plaster (hence why I may need a new l/friend, supposed to be going shopping!)
My cavity is 85mm (no pun intended)
Everything I see illustration wise shows a "H" install......
Do I support everything then....
Remove3 courses above gap
Install Catnic Lintels level on padstows either end securing with mortar. Allow 24hrs to set
Install soldier course upto existing brick work ensuring gaps filled with mortar. Allow 24hrs to set
Remove props, cross fingers and spend night in hotel?????

 

[monkeysDIY]

If using a lintel, its very important to support the centre section during install and untill the bricks you replace have gone off. Otherwise it will bow

Woody, thanks. I thought these were supposed to NOT bow????
I am think of possibly leaving the window out for periods.... obviously not when the BC come and have a look.... but when conservatory is in and a nice open kitchen/ conservatory is avail....

 

[^woody^]

These lintels bow as the bricks are re-inserted and load added to the lip. And as the bricks are tapped, the lip vibrates and mortar compacts and the bricks tip forward.

I'm forever seeing the soldiers or first three couses above lintels (new build and replacement) tipping out, and the lintels bowing, when clueless brickies haven't bothered to support the lintel during construction.

You don't need padstones for lintels in this instance

BTW, shytalkz (and most engineers) has to have regular time off to count all their fee earnings, and keep in a lower tax bracket from earning too much.

 

[monkeysDIY]

Poor old Shy, I would be happy to help him count......

Thanks, so me being slow.... what prevents this happening after install - mortar sticking it together?
Wouldn't want to have to provide hard hats when the window is removed!!!
So the Lintel "Mater" provided pic of... just sits on existing brickwork with small mortar bed to the tune of 150mm plus
Regarding my install steps.... am I correct plus keep a support to prevent bowing...

 

[^woody^]

Once the brickwork has gone off, then there is no bowing, as the wall has an element of self-support from compression of the hardened mortar joints