No collar in cut roof query ?

joebre

Attic conversion taking place during build of new bungalow. Cathedral type ceiling in mezzanine with no 2.4m horizontal ceiling. Some say that 2.4m ceiling is a recommendation rather than a requirement. I personally don't agree with that. There are plans for 2 bedrooms on either gable. Shocked to see no collar ties ! What should have been done here ?

Also the Commencement Notice was submitted with Compliance documentation. I am advised that a Preliminary BER was not submitted ! Not sure of this is the responsibility of the Certified Assigner or whether it was a mistake by Building Control to validate the application with it ?

out it ?

Penn

They should have at least used diagonal timber ties from the joists to the rafters behind the stud partitions to prevent/reduce roof spread. That's what I'd be expecting to see anyway.

sydthebeat

https://www.boards.ie/discussion/2058353943/no-collar-in-cut-roof-query

what do you mean "out it"?

in regards to the prelim BER, when the BCARs online system came in first, different LAs had different opinions on what was required, so this build may have fallen into this time period. Its the local authority at the end of the day who is responsible fo requesting the documentation and deciding whats valid or not.

on the actual build, to be pedantic its not an "attic conversion" if its constructed at the time of the original build, you can only convert something which already exists. But at a lack of any other way to call it, it complies with nothing. Its not habitable, its storage space with a fixed stairs. Whether a collar tie was required was down to the certifiers opinion. The rafters do look to be significant (9x 2s?), and the span between supports may be allowed under eurocode 5.

chooseusername

https://www.boards.ie/discussion/comment/122207433#Comment_122207433

"what do you mean "out it"?

Also the Commencement Notice was submitted with Compliance documentation. I am advised that a Preliminary BER was not submitted ! Not sure of this is the responsibility of the Certified Assigner or whether it was a mistake by Building Control to validate the application with it ? (without it ?)

joebre

https://www.boards.ie/discussion/comment/122207968#Comment_122207968

You are right. My edit appeared below the 2 photos. Yes, I meant 'without it'

I since see that the Assigner has submitted a Part L Compliance Report. That would only appear to be good for each of the individual elements ?

Surely a DEAP assessment would need to be done to determine the potential rating ?

sydthebeat

https://www.boards.ie/discussion/comment/122212411#Comment_122212411

In order for the assessor to send in a Part L finished report showing that it is in compliance, they're have to do a deap assessment.

It's likely they have reproduced the "part L" report generated from the software, but without seeing it, it's not possible to tell.

I can't see any local authority accepting a part L report which doesn't have the deap reports as part of it

joebre

This is all they submitted !

sydthebeat

https://www.boards.ie/discussion/comment/122213256#Comment_122213256

hang on, why does that spec say "existing solid stone walls"?

your OP states "during build of new bungalow"

so was this a new build dwelling or not?

Mellor

https://www.boards.ie/discussion/2058353943/no-collar-in-cut-roof-query

Ceiling height of 2.4m is a guidance, not a requirement. It should be followed, but you can deviate with suitable justification.

A collar tie being required or not is a structural matter. There's a couple of variables. Would expect to see something is lieu of it, if the design was a vaulted roof.

joebre

https://www.boards.ie/discussion/comment/122218792#Comment_122218792

It's a new build. The reference to stone is made by the Certified Assigner. There's a small section with stick-on stone cladding. I also agree with comments that it's not the conversion of an attic if it's being built at the same time as the main house.

sydthebeat

Nothing makes any sense here.

It can't be "existing solid stone walls"

So either the council didn't bother to read anything submitted, or the build was a renovation of an existing structure

joebre

https://www.boards.ie/discussion/comment/122224034#Comment_122224034

It's a new build with accommodation being provided ( velux windows to rear) in an approved bungalow at the time of original construction. The specification is given by the Architect as part of his Commencemnt Notice with Compliance Documentation. This was accepted by the Council. No preliminary BER was submitted. The clients have no idea what they are getting.

Mellor

https://www.boards.ie/discussion/comment/122224788#Comment_122224788

I think you've missed Syd's point.

The spec above says existing stone. A new build can have stone, but it cannot have existing stone. Existing implies is already exists which means conversion, addition or alteration of and existing structure not a new build.

You comments above don't really clarify it.

an approved bungalow at the time of original construction.

It's clearly not a bungalow. But reference to being a bungalow and original construction adds further confusion. Was originally constructed a bungalow, and this is post construction additional work.

joebre

Some of the confusing text is by the Assigner regarding ‘ existing stone ’

This is a new bungalow under construction is an estate of similar bungalows. The cross section drawings show a truss roof. A first floor is being provided at the same time as the initial build.
It would appear that the depth of the ground floor and the roof pitch do not allow sufficient head height. Consequently, the builder has omitted any collar as this would further reduce head height.
The roof does not appear to be structurally safe to my eye.

sydthebeat

Joebre, may I ask what your inclusion in this process is?

Are you an inspector engineer working on behalf of perspective purchasers?

We cannot comment on structural issues here, read the forum charter.

But I will revert back to my first comment where this type of construction may be possible depending on the sizes of individual elements.

All the stuff about "prelim bers" is just red herrings. As far as the vendor is concerned, if the local authority validated the commencement notice application then they are clear to start.

joebre

I am the Engineer called it at a late stage as the buyers have concerns about the roof. I agree that the CN was validated without a preliminary BER so the builder was free to start. The builder is now telling them that there is no need for a final BER as they are not selling the house. I am not sure what right I might have to request calculations from the Certified Assigner to back up his design for the roof ‘as constructed’

sydthebeat

https://www.boards.ie/discussion/comment/122246250#Comment_122246250

well the builder is completely incorrect, as a BER is required on a new home upon first occupation.

plus, theres no way the assigned certifier will know if it complies with Part L with a "new final" BER assessment being carried out.

have you been engaged to provide Part A certification, or advise the builder as to how to provide compliance?

If you think the roof is unsafe, you will need to advise your clients as such and describe why. if theres a deposit paid there may be contractual issues which could cause financial problems, so youd want to have all your ducks in a row.

If the builders certifier can provide certification with Part A then unfortunately your clients will be left with the choice as to whether to accept the certifiers certification or your advice.

at a minimum, if all this work is being carried out in contravention of the initial CN application, then you should advise the clients to request certification of exemption from planning regulations AND compliance with building regulations.

sydthebeat

just a few more things on this.

1. Commencement notice applications are only to do with building regs and have nothing to do with planning permission, so the planning status of the change to attic wont be dealt with through the assigned certifier process.
2. It is possible to submit alterations and changes during the build onto the bcar system, including design certification @joebre i am assuming you do not have access to these documents?
3. you say "there are plans for two bedrooms on either gable". do you mean official "on drawing" plans? was this a request by the purchasers, or just done by the builder? if so, was this replicated on all dwellings in the development?

Tefral

Id question the absolute requirement for collars here. The main fuction of them is to stop the downward force applied to the roof from damaging the external walls. You have knee walls here and also the Ceiling Joists creating the bottom of the Triangle.

Would I put them in doing my own house? Yes.

Would I think they were absolutely necessary… probably not. While there can be big windloads in Ireland, we dont have snow sitting on our roofs for 3 months of the year….

In the latter, you'd prefer the rafters to be screwed to the ridge as well as nailed to be honest.

joebre

https://www.boards.ie/discussion/comment/122244206#Comment_122244206

I have been asked by the buyers to crry out an inspection with a view to completing a snag list. I was asked at the last minute with second fixng snd footpaths remaining. There was nobody engaged before me.

https://www.boards.ie/discussion/comment/122246317#Comment_122246317

No. i'm engaged by the owners of the site and the ones who got the build to quoue and build their house. They owned the site for a couple of years and engaged the builder who had built the other 10 houses.

Most other houses had similar work done on their attics during the course of the build. They do not have gable windows but have Velux windows to the rear.

I do not have any more access other than the Part L compliance report that I posted earlier.

sydthebeat

https://www.boards.ie/discussion/comment/122251850#Comment_122251850

Most other houses had similar work done on their attics during the course of the build.

thats the nub then.

its highly unlikely the assigned certifier for the scheme would let so many roof constructions happen without proof of Part A compliance. There is likely to have been additional information submitted to the CN to reflect this, and thus Certs of completion provided to the houses which are already finished.

as to your engagement, slightly unusual. A snag list is carried out on completion, not earlier. its questionable as to what power of recourse you have if you spot something less that optimal.