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Which Lintel


Ed_MK

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Hi All,

 

I am about to order the windows and doors for our house. The bricklayer will be starting soon,

and it got me thinking about support around the top of windows and Doors.

 

the house is a timber frame and has a lower storey of Brick skin ...upper storey will be cement render on 

Renderlath

 

Some of the windows (in fact most) have only 4-5 courses above them (ending in brick on edge) ..then it comes to renderlath.

So...

I am presuming the windows that only have renderlath above them do NOT need a support or close off at the top in any way ,

but if this is the case..do they still need some form of cavity tray?

I guess windows that have brick above them will all need a lintel or catnic of some sort ..I am thinking the one that is made for a single brick skin

(see attached pic) ...but again; do i need a separate cavity tray above ? ...and will LIGHT duty lintels suffice for just several rows of brick?

(there really is only one window that has a LOT of brick above it)

 

The bifold opening in the Sunroom is about 4 metres (or just under) ...it DOES have a couple of rows of brick above it, it was going to be a brick apex,

but we have decided to render it instead for ease ...how should i cope with that span ?

 

On Catnics website ...it shows a lintel for timber frame ....but they appear to have CUT into the breather and installed some DPC? (or something) under it to
drain to presumable some weeps . I know potton are not crazy about that silver layer on the TF being cut at all ...is this standard practice ?

 

 

lintels_openings.JPG

catnics.png

Edited by Ed_MK
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2 hours ago, Ed_MK said:

Catnics website ...it shows a lintel for timber frame ....but they appear to have CUT into the breather and installed some DPC? (or something) under it to
drain to presumable some weeps . I know potton are not crazy about that silver layer on the TF being cut at all ...is this standard practice ?

 

Catnic have been in business far longer than Potton. 

 

Take from that what you will. 

 

I would use the standard TF lintels from Catnic - Condells are the cheapest for these.

 

That bifold is going to cause a headache though ..!! You will need to build the white render section with 75mm blockwork so the render can be applied inside the framing.

 

Other (strongly recommended) option is make that whole apex rendered and framed with timber to match the rest of the render panels. 

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Thanks Peter ...I probably should have mentioned 

in the sunroom ..those 2 big triangles are WINDOWS..or will be...and the surround bit at the top will be rendered 

..the brick will start just above the doors perhaps 2 courses .

 

I agree about the lintels ...and have been looking at that site already

 

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not again ...

I can see another RSJ coming on ....damn!

 

its not just the money for the RSJ ...or the £60 the online engineers charge for the report to go with it..

 

..its the fact that RSJ's look ugly as hell ...I mean it is alright in the chimney ....but how do i effectively "hide" it over the bifolds Peter?

 

its only a 100mm brick skin, with 50mm cavity and then 190mm TF ...but of course the lintel will be supporting the Brick and windows on the outer 

edge ...so it has to be at the front 

 

i didnt even want those windows there....they wife swapped them in when she removed the 2 x velux in the roof from the plan
...as the last time we had them they leaked and were pigs to clean etc

 

 

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You can’t use an RSJ there as it would show - it has to be a lintel but to get the strength it needs to have a minimum number of brick courses - usually 3 or 4 or 1 block - before you add anything else. 

 

Have you ordered windows as there is no way you can put a brick column in the middle of a 4m span. It has the ability to twist the lintel and that falling could kill someone. 

 

All of these lintels should have been engineer specified before the build was signed off as starting by BCO. 

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i think i have confused a few people ...sorry

 

the top is ALL render and not brick...see the yellow area below,

its actually going to be an oatmeal colour ..to match the top of the rest of the house.

If the render is like the rest will be ..The renderlath  will be on 50mm standoff from the TF and

then rendered another 15-20mm and will finish about 40mm shy of the brick courses below.

which are being finished with a brick on edge.

 

the render is not adding any weight as its on the TF, but Peter is right the Windows won't be light

and then of course i need at least 1 course of brick to hide/contain some form of support..but that 

will be the only masonry on top

 

I measured the aperture before and it is 3.6m ...so a little shorter than i said.

 

Originally on the plans this was not a window at all and was a full rendered panel ....thats probably why.

they were added by my wife as when she removed the Velux ...it would have been a bit "dark" ...and it IS a sun-room 

..allegedly

 

 

 

render_sunroom.jpg

 

so these would be no good ?
 

http://www.less2build.com/lintels/ig-lintel-all-types/ig-lintels-timber-frame-all-types/ig-lintel-l750-timber-frame--3600mm-50mm-cavity

 

http://www.less2build.com/lintels/Stressline-Lintels-All-Types/stressline-timber-frame-lintels?product_id=3998

 

http://www.less2build.com/lintels/catnic-lintels-all-types/catnic-timber-frame-lintels/catnic-lintel-ctf5-timber-frame--3600mm-50mm-cavity

Edited by Ed_MK
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If it is just rainscreen cladding above (tiles, rendalath, render board etc) supported on the timber frame you will not need a lintel.  You need to work out how the interface of the rendalath and brickwork will be.

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Well, i sort of understand the "arch" theory ...

but i have attached below an image of an IDENTICAL house built several years ago.

 

As you can see the windows APPEAR to have PERHAPS 1 or 2 courses above them ...Maximum

except for that lounge window which has over 20 !

 

at the rear (which is my actual house ..its the same setup 

Kitchen door, Kitchen Window and Patio doors (you cant see them but they int he dark on the left)

all have only 1 or 2 courses above them

 

the exception of course ..is the bloody sunroom :( ..which again will have 1/2 courses

and the DAFT triangle fixed windows 

 

PS
the side the chimney is on has NO windows, and the opposing side has only ONE  window upstairs,

which is of course in the rendered area

 

 

 

house_rear_sunroom_windows.jpg

Example Exterior 1.jpg

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Are you not confusing courses with a wall, just because it looks like a wall doesn’t mean it has any bricks

that picture you put up of the part built house with the triangle windows has not got any brickwork around the windows

you will probably find it has the timber frame(structural) then a dummy frame or just packed out timbers to bring the outer face in line with the lower portion. 

 

Does potton not supply these details to you ??

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Whilst a number of people are trying to help here, when it comes to structural elements of a build you need to obtain sound professional advice that is backed up with Professional Indemnity Insurance just in case anything goes wrong.

 

The advice given by the forum and its members is just that - it’s advice. It does not replace an architect or structural engineers calculations and knowledge which are based on plans and factors that members may not be aware of just from looking at photographs. 

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6 hours ago, Russell griffiths said:

Are you not confusing courses with a wall, just because it looks like a wall doesn’t mean it has any bricks

that picture you put up of the part built house with the triangle windows has not got any brickwork around the windows

you will probably find it has the timber frame(structural) then a dummy frame or just packed out timbers to bring the outer face in line with the lower portion. 

 

Does potton not supply these details to you ??

 

Hi Russell,

 

yes thats the back of my house ...the top section doesnt have any bricks; its Render on lath (around the windows) - which isn't there yet...so you are actually looking at the TF skin.

Around the bifolds (and for 4-6 inches or so above them) that will be brick/brick on edge ..so it can meet the bead for the render...not sure what you mean about a wall not having bricks though ..that spun me :)

 

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6 hours ago, PeterW said:

Whilst a number of people are trying to help here, when it comes to structural elements of a build you need to obtain sound professional advice that is backed up with Professional Indemnity Insurance just in case anything goes wrong.

 

The advice given by the forum and its members is just that - it’s advice. It does not replace an architect or structural engineers calculations and knowledge which are based on plans and factors that members may not be aware of just from looking at photographs. 

 

Tx Peter.

 

I was just looking for some advice ..honestly ...its just i always PRESUMED that any window or door needs some sort of capping or lintel above it ...With TF as you know the rendered section are well...self supporting; as they are fixed to the TF completely. These Potton "heritage" designs come in a variety of options for allsorts of external coverings ...its just we went for render top/brick bottom (which is the most popular).

The sunroom windows apart (because they are a monster of our own making) ...the other windows on these heritage generally have VERY LITTLE brick above them downstairs ...as the brick/render divide finishes just above the openings 90% of the time.. So a small window may only be supporting 2 rows of say 3 brick and a brick on edge above (or tile crease as some choose) ...even the LARGER windows may have just 10 bricks and a further row of brick on edge above that ...so 20 bricks maximum....

 

But still needing support of course...which is why i was thinking of light/medium duty catnics ..as i again presumed that these would be more than enough ..if not TOO much to support a single/double row of brick

 

Pottons architect and advice stop firmly as the TF/Insulation phase ends ...Roof, Cladding, Brickwork, Windows and everything after that is down to the builder/buyer..plans typically use the phrase "Not By Potton" when they are describing various options you can take or choices you can make ....You do get a guidebook ...but its very basic, again as there are so many options ...it would be like War and Peace if they put them all in there ....so I understand.  I am not knocking Potton (honestly)...but like all sales companies you get SOLD on a dream at a Trade Fair and price is in black and white that is achievable and so you go for it ...But as you get more involved...you can see that there are a variety of "packages" that come on top ....things that a layman (and woman) would believe are included (in ignorance) ....Planning Application help, Windows, Stairs, Internal Doors, External Doors, Skirting, Architrave, etc etc ...external finishes of course too , even the chimney and fireplace ..LOL (which is what the wife loved about it) ...then on top of these options is the Part or Fully Managed Options ..which is in essence a project manager for part or all of the build ...and then the ultimate TURNKEY SOLUTION ? ..Which means you do nothing (i presume)

 

The only issue is ...by the time you finish, the price will have EASILY doubled...so you start to take things off ....Then you realise that the ESTIMATED finished build cost (that you thought you may JUST be able to afford)...was based on tradesmens prices that are several years old and are UK average ...Internal plastering for a full house is rarely under £5k including boarding and there is no bricklayers to be had for £300 a thousand, and unless you are using corrugated sheets ...getting a decent roof for under £10k is another "dream of ages past"

 

...so you take a little more off, then a little more to compensate ...and you get to where I am now .

 

I would never advise anyone NOT to go the self-build route ...but If i had one bit of advice it would be do NOT listen to those that tell you make sure you have 10% extra funds in reserve ..

15% tops ...It's plain BS. We have shopped HARD, had multiple quotes for all work and used this forum where we can, to see our most logical options, am stuck in every day painting, cutting insulation, doing external pipework and we are STILL expected to be 30% + over ....and this is a build that (so far) has had no surprises or dramas.

Don't sign for anything until you understand just how ESTIMATED your finished build cost will be ...

Edited by Ed_MK
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