Krend on timber frame

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scott.beaumont

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Pricing a krend job on a timber frame house the guys bought all the material and he has rendalath it all. It's a fiddlly one all up in Eve's, dorma windows, and wooden beams. It's about 200sqm he been quoted 35psm supply so he bought all the gear. I'm thinking 25sqm labour or day work 200 a day per plastered do you think this is reasonable thinking heading more day work cause it's awkward???
 
I would be very careful about putting Krend monocouche (if thats what he has bought) onto a timber frame. even using rendalath

the rendalath will take some basing to get it up to scratch coat
 
Renderlath is a complete cock to render over and will probly need two coats of base to get it good enough to mono
 
by the way if you go in at 25 the overall cost will be more than the guys who went in at 35 supply and fit especially with all the hp 12 going onto it and unless he has a trade account his mats will be well more than £10 p m s with all the vat on
 
With the price of rendalath - time it takes to install, the extra render basecoat needed to cover it..... then the TF shrinkage meaning it will crack anyway....... why doesn't everyone just batten, board and then render TF units now......?
it is faster and easier to put up, getting cheaper as the price of lath goes up. Gives a flatter easier substraight to render to and allows you to control the shrinkage.......
..... and if you use the right render systems, you can use a scratch finish..... (although thin coat is better).....
 
With the price of rendalath - time it takes to install, the extra render basecoat needed to cover it..... then the TF shrinkage meaning it will crack anyway....... why doesn't everyone just batten, board and then render TF units now......?
it is faster and easier to put up, getting cheaper as the price of lath goes up. Gives a flatter easier substraight to render to and allows you to control the shrinkage.......
..... and if you use the right render systems, you can use a scratch finish..... (although thin coat is better).....

This is what we do

We wouldn't install mono over a timber frame
 
Thought it was still the golden rule on Cem/aquapanel/calciate boards etc that you don't render in excess of the board thickness..?- so approx 12-15mm being the max- sort of rules out most renders bat the thin coat.

Monocouche job near me was done with cem board, and now cracking along all joints and blowing off the wall in places. Cost to put right is unthinkable.
 
Jasper - there is a right and wrong way to fit the boards.... most are bought as consumable boards and installed however the chippy, contractor, developer, main contractor, labourer wants - then rendered on......

You have to apply the correct render to a board - basecoat and mesh, then a finish coat! Render system suppliers all have approved boards (not all the same boards!)
The render thickness and type is defined by the render system supplier you use, but some boards can take thicker and heavier finishes (it is more to do with weight, than thickness).

Consideration has to be taken to the expected shrinkage of the TF, and allowances and movement joints installed to suit.

I suspect that the project you are referring to, has butted boards and then a scratch directly applied..... the TF shrinks and the boards rub and move, the cracks come through on the joints.... then depending on the render and the location, water gets behind and it starts to delaminate!

I will be more than happy to assist and advise further if you like (or just send you info in the form of an E Mail).....
Richard Lord - rlord@knauf.co.uk - 07918766577 - Knauf Drywall - Knauf Aquapanel Exterior Specification Manager.
 
i think ud struggle to earn ur money on 25 p/m. will def need a pricking coat, a ruled scratch and then top coat. and you said its awkward. daywork or give it a pass. and it also depends on the standard of the meshing
 
Jasper - there is a right and wrong way to fit the boards.... most are bought as consumable boards and installed however the chippy, contractor, developer, main contractor, labourer wants - then rendered on......

You have to apply the correct render to a board - basecoat and mesh, then a finish coat! Render system suppliers all have approved boards (not all the same boards!)
The render thickness and type is defined by the render system supplier you use, but some boards can take thicker and heavier finishes (it is more to do with weight, than thickness).

Consideration has to be taken to the expected shrinkage of the TF, and allowances and movement joints installed to suit.

I suspect that the project you are referring to, has butted boards and then a scratch directly applied..... the TF shrinks and the boards rub and move, the cracks come through on the joints.... then depending on the render and the location, water gets behind and it starts to delaminate!

I will be more than happy to assist and advise further if you like (or just send you info in the form of an E Mail).....
Richard Lord - rlord@knauf.co.uk - 07918766577 - Knauf Drywall - Knauf Aquapanel Exterior Specification Manager.

Been around the block with these systems for years mate,one of the major factors for failure with most of these systems is like you say the weight, but equally the wind load factor is an issue. Many systems still spec 9mm board on 600m centres, which imo wont stand up to much.

The job i referred to was a weber monlithic 2 coat scratch render, applied by a reputable company to an approved carrier board which still failed. i think you still take your chances in applying lightweight renders in excess of the board thickness. Just my opinion mind.
 
Scissors - do your Knauf systems require board joints to be filled and taped prior to base coat and meshing?
 
Jasper

the 600mm centres is a loose spec imo, probably the absolute minimum and maybe a cost cutting measure because the subframe has been erected with 600mm centres and then fixed the render carrier straight onto that.

The way forward imo is deffo sheath out the subframe with 12mm ply over the 600 centred frame, then once fully closed in, breather felt after this measure is in place timber grounds fixed at 400mm centres can be fixed vertically to take the render carrier board. using maite or sm700 then in a thin coat system with scrim jointing first then a full mesh coat and acrylic/sil finish

overall 6 - 8 mm render thickness

This is what we do and have had no issues with timber frame which will constantly move for its whole of life, expansion and contraction etc
 
Evening Guys
All timber frame manufacturers take into account the wind loads when designing their kits..... so each project has the wind loads confirmed at design stage.
We, specifying the Knauf Aquapanel Exterior, will make a judgement call based on the location of the project and ask for, or review ourselves, the wind load expected for the project. We then calculate the vertical batten centres behind the Knauf Aquapanel Exterior, based on our understanding of our boards deflection limits (as laid out in our BBA). In most central UK and non high wind load areas, battens set at 600mm ctrs are suitable (these currently must be fixed back through the sheathing boards into the TF studs)
As JFE says above, if all TF's had a min 15 mm OSB, or 12.5 ply sheathing board, the battens, boards and render could be applied into just the sheathing board at centres to suit the design.... However, TF manufacturers are feeling the pinch and install 9mm OSB boards (at the moment), which are what is needed for the TF sheathing and take no consideration for cladding........
When the vertical battens need to be set at closer centres (mainly for wind loads, but also to suit impact requirements on specific sites), we advise the use of a horizontal battens, at defined centres, into the TF studs, then vertical battens at closer centres into the horizontal..... this also allows boarded systems to be packed away from the TF to align with block work or other cladding.
 
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Scissors - do your Knauf systems require board joints to be filled and taped prior to base coat and meshing?

We offer a tape and joint for use with the Knauf Aquapanel Exterior Boards, however they are not always needed.

If used, you can leave the boards up without any render finish for up to 6 months, then come back clean down and render. This sounds great to Architects, Developers and MC's who can create a weathertight building and continue with the insides, then finish the rendering / cladding when the weather is better...... but in reality, most board and render straight away (better for the renders as well.......)

Some of our approved render system partners will not use the T&J system and have a heavier basecoat mesh, others will use it (or their own) and then use a lighter gauge basecoat mesh.
Using T&J does add extra strength to the walls, but is not always really needed when using Knauf Aquapanel Exterior - refer to the project specs.

The T&J system is always advised for soffits, with the upward and suction pressures.
 
Evening Guys
All timber frame manufacturers take into account the wind loads when designing their kits..... so each project has the wind loads confirmed at design stage.
We, specifying the Knauf Aquapanel Exterior, will make a judgement call based on the location of the project and ask for, or review ourselves, the wind load expected for the project. We then calculate the vertical batten centres behind the Knauf Aquapanel Exterior, based on our understanding of our boards deflection limits (as laid out in our BBA). In most central UK and non high wind load areas, battens set at 600mm ctrs are suitable (these currently must be fixed back through the sheathing boards into the TF studs)
As JFE says above, if all TF's had a min 15 mm OSB, or 12.5 ply sheathing board, the battens, boards and render could be applied into just the sheathing board at centres to suit the design.... However, TF manufacturers are feeling the pinch and install 9mm OSB boards (at the moment), which are what is needed for the TF sheathing and take no consideration for cladding........
When the vertical battens need to be set at closer centres (mainly for wind loads, but also to suit impact requirements on specific sites), we advise the use of a horizontal battens, at defined centres, into the TF studs, then vertical battens at closer centres into the horizontal..... this also allows boarded systems to be packed away from the TF to align with block work or other cladding.

Probably a silly question but what's a wind load???????
 
If you don't know the answer, it is not a silly question......ask! Thanks Artisan! (bit of a problem with some posts / comments on this forum... not everyone knows everything - I learn everytime I come on here!)

A wind load is the effect that the wind has when it blows on a building..... it can put pressure on a wall when it blows directly at it, pull at a wall if it blows past it, and creats both pressures when it hits a corner!

These wind loads are even more complicated on external soffits (ceilings) and even more in a tunnel area (like a underpass for carparking behind a building, for example) ........

Wind loads are much higher in western and northern areas of the UK, and most coastal areas, so Jaspers comments about problems in the SW may be a result of some wind loads as well.

Most buildings in the UK (and the various products used) are massively over engineered and these pressures are usually ignored as a result of the various checks during design (this is why BBA certs are so expensive, but give peace of mind). But with more and more cost cutting, design and build / self build contracts, some products are being incorrectly used.
 
Can't you use mono over aqua panel? Is this where a 2 coat system is used ....a base coat 5-6mm then one coat of mono ?
 
You can put K Rend and Parex Mono onto Knauf Aquapanel Exterior - as approved by them..... as you say apply 4 - 5 mm basecoat and mesh (HPX and Maite respectively), then a 11 or 12 mm Mono scratched back to 9 or 10mm.....

We advise that you take care with the TF structures with Mono, and make sure that the wall areas are small or split up using movement joints.... Mono is a fairly brittle finish, so any excessive movement will crack..... it is usually fine of housing.

That said, both K Rend and Parex are now prefering to spec their thin coats onto boards on TF now anyway......

There are no scratch render systems onto a board with BBA certifcation. (as of today, who knows what the BBA are working on......)
 
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You can put K Rend and Parex Mono onto Knauf Aquapanel Exterior - as approved by them..... as you say apply 4 - 5 mm basecoat and mesh (HPX and Maite respectively), then a 11 or 12 mm Mono scratched back to 9 or 10mm.....

We advise that you take care with the TF structures with Mono, and make sure that the wall areas are small or split up using movement joints.... Mono is a fairly brittle finish, so any excessive movement will crack..... it is usually fine of housing.

That said, both K Rend and Parex are now prefering to spec their thin coats onto boards on TF now anyway......

There are no scratch render systems onto a board with BBA certifcation. (as of today, who knows what the BBA are working on......)


Flexible building - flexible basecoat - flexible finish :RpS_thumbup: stay safe
 
If you don't know the answer, it is not a silly question......ask! Thanks Artisan! (bit of a problem with some posts / comments on this forum... not everyone knows everything - I learn everytime I come on here!)

A wind load is the effect that the wind has when it blows on a building..... it can put pressure on a wall when it blows directly at it, pull at a wall if it blows past it, and creats both pressures when it hits a corner!

These wind loads are even more complicated on external soffits (ceilings) and even more in a tunnel area (like a underpass for carparking behind a building, for example) ........

Wind loads are much higher in western and northern areas of the UK, and most coastal areas, so Jaspers comments about problems in the SW may be a result of some wind loads as well.

Most buildings in the UK (and the various products used) are massively over engineered and these pressures are usually ignored as a result of the various checks during design (this is why BBA certs are so expensive, but give peace of mind). But with more and more cost cutting, design and build / self build contracts, some products are being incorrectly used.
Thankyou...:RpS_thumbsup:
 
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