Internal Insulated slabs - window frame dimensions?

G

Goldie

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Hi,

I will be fitting insulated slabs on the internal side of external walls of a new build. Are the slabs normally returned around the window and door reveal? If so does that require a window with a wider than normal frame dimension( to still have a normal internal visible frame after the slab is fitted)?

Any blocklaying changes required for the external leaf?

Or what is the correct approach for fitting slabs but that is also aestetically pleasing afterwards?


Thanks,

Goldie
 
Goldie, this is information more properly sought from your architect.
You don't say what the external walls or what the slabs are made from.
Are you another self builder with no drawings and no professional oversight?
 
Onq,

With respect, if you are either unwilling to help or have nothing beneficial to add please do not reply. From previous posts it would appear to me that there is either a vested interest or you have an obvious negative propensity to direct labour build projects.

This is a homes and garden forum to encourage knowledge, in the majority of cases the information is provided without criticism, unhelpful replies do not benefit anybody and only serve to hijack a thread and not lead to the sharing of information originally requested.

Regards,

Goldie.
 
Here, Here.

Onq,

With due respect, it seems you have a serious chip on your shoulder towards selfbuilders.

At the end of the day, no matter how good a professional you have on site it is always good to have heard a few other peoples opinions on the matter as well. At the end of the day self building isn't rocket science, and provided you know when and who to call on for professional advice when required, a very satisfying experience.

As Goldie has said if you are not willing to help or have nothing beneficial to add please don't bother replying to posts.

PS- you should probably remove/edit your other recent comment re: showers as your info appears to be incorrect!
 
In fairness onq has a point too, a lot of recent comments are being posted by people who are having trouble with contractors as a result of direct labour agreements with no oversight by building professionals. Only now in the case of dispute are the views of the professionals being sought and valued.

Goldie - to answer your question you would normally use a thinner section of insulated plasterboard to your reveals as most of your thermal bridging should be eliminated through the use of insulated cavity closers at all opes and drafts eliminated by the correct application of your air tightness membrane.
Suggested detail: [broken link removed]
 
Last edited:
yes i returned the slabs around the window revals, the blocklayer left the window openings wider on the inside as opposed o the outside for this reason, i dont think they all do though, as for the doors, do you mean the front and back door or the internal doors, the internal door ways will generally be in the block wall, one that you wont be insulating, which was my case anyhow,, this was just sand and cement .

i had guys slab my house and they were quite good in their wokman ship, they returned the slabs nicely into the windows, prior to this i fill ed the gaps with expanding foam when the windows weer fitted, one thing though. even though it was drying well and i only had very very low heat on i still got cracks on the joints of the slabs on the walls, mainly starting from the window board down.

hope this helps
 
quick question
Is it necessary to have anything other than mechanical fixings to hold these insulated slabs onto a concrete wall (new build)
Cheers
 
On my recent extension/refurb I insulated the reveal. This will stop cold bridging. There is also a thin board that you can get for reveals. With regard to the extra space around the frame I asked the window fitter to leave a 10mm gap around the window
 
i dont believe you need anything else except the metal mushrooms, as long as the block work is good,

some people use bonding, i did not
 
All you need are the metal fixings.

The plastic ones are not suitable as they can melt during a fire, leaving the slab unsecured.

It is recommended to put a firestop along the bottom of the boards to prevent a fire getting up between slab and wall. Options here would including something like bonding, fire foam, or intumescent silicone.
 
Goldie said:
Onq,

With respect, if you are either unwilling to help or have nothing beneficial to add please do not reply. From previous posts it would appear to me that there is either a vested interest or you have an obvious negative propensity to direct labour build projects.

<forum summary snipped>

Regards,

Goldie.
Click to expand...

Goldie,

You seem to have missed the whole point of my post.
Suggesting you should use a professional in the building process dosn't mark me out as someone who's unwilling to help or who has said nothing beneficial.
On the contrary, I have just given you competent professional advice and not charged you for it.
You are free to ignore my advice, but you may come to rue the day you did so if something goes wrong during the build.
Then you may be back here posting - like one recent post - and asking where the responsibility lies - it lies with you.
In a self build with no main contractor or professionals retained to conduct limited inspections and no working drawings you are taking on the roles of;-

  • architect
  • structural engineer
  • m&e consultant
  • main contractor
  • Client [H&S]
  • Project Supervisor for the Construction Stage [H&S]
The fact that you may not know this only underlines my point.
I don't suggest you involve professionals lightly, but following years of experience cleaning up the mess left by others I've seen what follows when inexperienced and unqualified people involve themselves in technology without doing the necessary research.
have you commissioned a set of working drawings? A doors and windows schedule? A short specification?
Have you read any current building technology books to become familiar with the details you should be installing?
Have you read the building regulations and the approved details, both freely available for download on the http://www.environ.ie/en/ website?
If the answer to all these answers is NO then would you trust you to build your house compliantly?
Think twice. Cut once.

ONQ
 
rmdt said:
Here, Here.

Onq,

With due respect, it seems you have a serious chip on your shoulder towards selfbuilders.
<snip>
At the end of the day self building isn't rocket science, and provided you know when and who to call on for professional advice when required, a very satisfying experience.
<snip>
PS- you should probably remove/edit your other recent comment re: showers as your info appears to be incorrect!
Click to expand...

I have a problem with inexperienced and informed persons going anywhere near a building site - yes.
Experienced and informed persons, that's a different matter.
My problem doesn't stop at self-builders, but also persons acting as Main Contractors, who've never learnt the right way to do things under the building regulations 1997, never mind the current regulations, and there are a surprising number of these characters around.
In that regard a self builder who has retained professionals to produce a set of working drawings to follow can end up being streets ahead of a so0called "experienced contractor".
Experience only counts if its shown you how to do things the right way.

ON your other point, self building needs to comply with the building regulations.
When you've read the Technical Guidance Documents and the Approved Details on the http://www.environ.ie/en/ website in full, then you can tell me whether or not its rocket science.
Unless you're familiar with the requirements of these documents, the purpose of which is to show prima facie compliance under the law [but may not be the only way to achieve compliance] then you won't see where I'm coming from.

My original point was trying to show that the OP's question wouldn't have arisen if she had called in professionals "when required".
That time is "before going to site", not "during the build" or "afterwards".
And even with a good set of drawings, you still need good tradesmen to do the work and a good contractor to co-ordinate ithe work, support the tradesmen, organize insurances, update the Health and Safety plan and keep the project on time and within budget.

As for the re: shower comments I'll review it - I'm happy to correct any misinformation I may have inadvertently posted, and grateful for your correction - thanks.

ONQ
 
rmdt said:
Here, Here.

Onq,

<snip>

PS- you should probably remove/edit your other recent comment re: showers as your info appears to be incorrect!
Click to expand...

rmdt,

What re:showers thread are you referring to?
I've looked and I'm not seeing it on my "all posts" file for me on this website?
Could you clarify please?

TIA

ONQ
 
rmdt said:
Here, Here.
PS- you should probably remove/edit your other recent comment re: showers as your info appears to be incorrect!
Click to expand...

I found the thread here and made two replies to it.

http://www.askaboutmoney.com/showthread.php?p=890974#post890974

The post I made was couched using terms like,

"I think... perhaps in a different context ...I seem to recall...As far as I can recall .. theoretically..."

I wasn't stating it as fact, so I saw no reason to edit it - let the original post stand, warts and all.

:)

ONQ
 
Hi Goldie,

I had the same problem myself when I was slabbing and my plasterer informed me that he found that the best way was to dab on standard 12mm slab around the reveals for windows and doors.
He said he found that where people had returned their cosy-board in to the windows it was sometimes difficult to skim the window in square as the blockwork around the windows could be slightly out and if securing the cosy-board to the the blockwork with the metal mushrooms it will follow the line of the blockwork, whereas if you dab on you can square up the pieces around the window as you put them on using a square.
Worked well for me and all the reveals/windowframes are dead straight with the same amount of frame showing each side.
Obviously it does mean that the reveals wont be insulated but you cant win everyway I suppose
 
Mister Mac,

You may not just end up with cold bridges if you do that.
You can end up with damp and blackspot on the window reveals.
If moisture gathers behind the board it can migrate to the insulation.

ONQ
 
Mister mac,
This sounds like a lazy plasterer, warm board can also be dabbed on square. It takes a little extra work to rebate the insulation to allow a snug joint at the corner where reveal meets the wall sheeting. There is Zero point in having lovely square reveals that allow thermal bridging and heat loss or as Onq suggests a cold spot that allows condensation and possible dampness.
There is also a small factor of vapour barrier and airtightness to be factored into the equation, Part L & F of the Building regs should be read & understood in their applications.
 
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