Fire safety compliance and wooden cabin

S

sonyaoldham

Guest
Hi,

I was wondering if anybody had any experience of building a wooden cabin which is being used for a business. I am erecting a 40m2 cabin for use as a clinics and spa. I am plasterboarding the inside of the cabin for fire safety compliance but they also want me to concrete block one wall as it is 2m from our house.
Besides the ugliness of it and the fact that it defeats the purpose of putting a wooden structure up, it also seems to me that it wouldn’t work, my carpenter has pointed out that the wall would in fact direct any fire up to the most combustible part of my house…the roof.
I am hoping to persuade them to let me use a fire retardent varnish/paint as there are several out there that meet the class 0 standard, .
I think it would help if I could give them other case studies of cabins being used for business in Ireland.
If anyone knows of anyone who has been in the same position or could offer any advice, I would be very grateful.

Thank you,
Sonya
 
Timber frame is perfectly fine for construction. What you need to do is pay particular attention to the fire rating of the materials you are using. It has far less to do with the combustability of the materials but more to do with how they can slow the progress of fire and contain smoke - enough to allow occupants time to escape.

Ensure that your carpenter install fire breaks to the cavities, regardless of block or timber frame there should be NO spread of fire tot he roof through the cavity. If you are constructing with proper fire breaks and use double plasterboard or special fire rated plasterboard you can get up to 1 hour fire rating and more.

If it remains a serious issue you could build the concrete block wall and clad the exterior with the same timber cladding that you are using for the rest of the structure.

BUT ensure your carpenter knows what he is doing in relation to the firebreaks and cavity closing. Get a certificate of compliance from your engineer too, as you will be required to meet current building regulations with this structure.

Good luck!

Sean
 
You're the second poster this week asking for comments while giving out little information

  • Who has requested you to install plasterboard - a Fire Officer?
  • Do you have planning permission for the cabin?
  • Do you have a fire safety cert application [FSCA] lodged for the cabin?

Fire safety of occupants in small single storey buildings requires the following:

  • no sleeping occupancy
  • early alarm in event of a fire
  • alternative means of escape to the public domain

The wall may be required:
  • to prevent the spread of fire to the house
  • to allow persons escaping from the rear of the cabin to get out past it and the house to the main road
  • to comply with structural fire rating requirements

As your cabin isn't for residential office use, it appears fall under Other Non-Residential in Table A2 of TGD B and I'm assuming its unsprinklered.
This seems to need a structural fire rating of 60 mins.

So perhaps the plasterboard has another function, apart from reducing surface spread of flame - it may be needed to raise the integrity and insulation of the structure to FR60.
 
Hi Thanks for the replies.


  • Yes the plasterboard is at the request of the fire officer.
  • Yes i have planning permission
  • Yes i have an application in.

  • There is no sleeping occupancy
  • There will be an alarm
  • There is an alternative means of escape.
It is 40m2 2 rooms, and a toilet, the main room has a door to the outside and 3 windows, then a connecting door to the hall where there is another exit, the second room has a door to the hallway to the exit and one window.

There is no means of escape on that side and the wall i think the wall would be to prevent fire escaping to the house (but my carpenter thinks it would only direct it to the house.
While researching yesterday i came across external sprinkler systems so i am hoping either the fire retardent and/or a sprinkler system will satisfy the conditions.

Could anyone recommend an external fire retardent or sprinkler system?

Thank you,
Sonya
 
Forgot to say it's not timberframe but a wooden cabin.
 
Normally the FO tells you why he's asking for something, but if he did, again, you didn't inform the forum.

If you're dealing with a Fire Officer [FO] you're already in the hands of an expert and you should be taking advice from either an architect competent in dealing with FSCA's or a specialist Fire Safety Consultant.

Its probably not a good idea to be taking fire safety advice from a carpenter, unless this is a later career choice and he's well versed in Fire Safety principles and methods.

I suspect that the imposition of the wall is to allow passage past the cabin and/or prevent radiative heat igniting the house.

I think you need to do a cost-benefit analysis on the sprinkler system vs timber clad wall option.

You give the impression of someone who has a "package" solution fixed in your mind [the log cabin] perhaps for reasons of ambience and marketing the product.

You appear as though you aren't flexible in relation to alternatives or how you might incorporate the fire officers requirements.

Independent design advice seems to be required at this point, but that's up to you - Im not telling you your business, only trying to get you over this obstacle.

Flexibility is very useful when dealing with Fire Officers, or indeed any Council Official.

They are, after all, the people who can say "yes", and lets face it, properly designed interiors with timber finish will give all the ambience you need.

Oh wait, the carpenter isn'ta mind-controlling timber purist Svengali-type is he?

<snap!>

You will awake at the count of three - 1... 2... 3!

<chuckle>
 
Hi,

My architect is dealing with the FO and so far i have been very flexible and still willing to be so, that is why i have been researching fire retardant paints/varnishes which are Class 0 rated which should bring it according to my research above the technical guidance (my house is 2m from the house):

Fire restrictions
Untreated timber (over 400 kg/m3) has a surface spread of
flame of Class 3. The Technical Guidance Documents to the
Building Regulations require that timber cladding is not
fixed within one metre of a party wall or boundary unless
treated to achieve Class 0 spread of flame. Some other
restrictions for multi-storey buildings also apply but in
general timber cladding at least 9 mm thick is acceptable
under the regulations.



I would be willing to do this and also if necessary add a sprinkler system. I am looking at any viable option that will satisfy the FO and myself. Hopefully the FO will be willing to be flexible.



The cabin is for use as a clinic/spa and yes the aesthetics are important as it will be marketed as a tranquil retreat.


I wasn't going to go for a cabin inititally, i was going to convert the garage but my initial architect advised the cabin, yes for aesthetic reasons, and did the planning application knowing full well that it was a business and would need to meet fire safety compliance. I would have been quite happy to have placed the cabin further down the field if i had realised, but unfortunately i am not an expert on building only on chinese and western medicine. I am presently starting to lose faith in experts as small jobs/business don't seem to be their prioity and i seem to be paying them a lot of money for their expertise. I am nearly a year on from initially hiring an architect and not much further on.



The carpenter i think is using his common sense and also knowledge of wood when he made his statement as i have a bungalow, the roof of the cabin is at about the same height as the start of the roof of the bungalow.


The cabin will not have any fires/stoves and will also be non smoking.
Oh and I unfortunately won't have the internal ambiance as that will be plasterboarded.

Could you please do that mind controlling trick on the fire officer???? :)
 
No, it doesn't work on Fire Officers - I have tried it myself. :)

I think your architect might have been thinking of Irish weather and convenience in terms of siting the clinic close to the house.
I think he probably was thinking of your business not doing too well out of a converted garage and I agree with him - a quality product needs a quality setting.

The principles of fires is that you assume a fire begins in one place only.
You assume its a good thing for the roof to collapse because heat rises and takes it away upward.
You are obliged under the regulations to consider the spread of fire from one building to another due to radiation, not whether the roof burning through will spread it.
The spread of fire through radiation is assesed in relation to the unprotected area of the elevation facing the building and the distance between the buildings.
No matter what way you look at it, the fire officer isn't wrong and the carpenter doesn't negate the requirement for the wall by his argument.

I'm just a little worried that you went from garge conversion to "ambience" cabin and cannot seem to go back or find a middle route.
Is this you or your architect?
Personally I find a log cabin a little incongruous in relation to Chinese or Western medicine or indeed as a follow on from the archaic Irish retreat architecture.
Log cabins have become popular as holiday homes and "green holiday" resorts.
Places of retret and healing in Ireland go right back to Glendalough and the Gallarus oratory buildings - all stone buildings.
Natural stone would be my first choice for a finish in this country, but that's just me.

As for taking a long time the gestation period for even a small building can take a long time.

Re your professional costs, you should have had a fee proposal dealing with the standard process and quoting fees covering the following stages:

  • initial brief and design
  • pre-planning meeting
  • planning application lodgement
  • PA further information submission
  • appeal submission
  • fire safety certificate application lodgement
  • FSCA further information submission
Depending on what the FIS requirements are [I have seen a 3D study costing 5K asked for by one planner] you should know reasonably accurately what your fee outlay should be.
If you didn't see a reasonably comprehensive fee proposal, you should have asked for one and agreed fees and rates.

There can be a large difference between RIAI scale of fees and agreed fees on small work - unfortunately for the architect :-(
 
I don't understand, i think i am considering a middle route by researching other alternatives, if i can find a suitable alternative, i think it would be a lot nicer building than one with 3 wooden walls and 1 concrete blocked. I don't see how working out of a tastefully converted garage is the lesser of working out of a building with 3 wooden walls and 1 concrete. The thing is i do want a quality setting that is pleasing and comfortable and this is why i am on here looking for advice on ways forward...but without the concrete wall.
Cost is always an issue, especially when you are a mum trying to set up with no income coming in, would love natural stone building but.....!

I did agree fees and rates and briefs but the problem is if you are a lay person and do not know what is ahead of you, your are trusting and paying your professional to inform you and you cannot cover areas you do not know about in your brief.

There can be a large difference between RIAI scale of fees and agreed fees on small work - unfortunately for the architect :-( .......................and in the meantime i will have gone bust!!!! ...a year to get planning and fire safety cert???? I have nearly €900 going out a month in business loans!!!

So any suggestions on positive ways forward?????
 
If the concrete wall is for firebreak purposes, and that's what I am getting from your original post & the developments with ong, you need the concrete wall to prevent the heat (in case of fire, God forbid) from transferring sideways to the neighbouring property ie. your home OR vice versa.

If you have the space between the two structures, I can't see why a 9" (4" block on flat) wall built close to the log cabin and clad / disguised on the house side with similar timber sheeting as the log cabin exterior. This will give the protection from the radiant heat (look similar to the cabin,not so much of an eyesore) and may satisfy the Fire Officer's concerns.

As your architect to sketch it out and submit for the consideration of the FO.

In fairness your architect and the FO should be working towards a cost effective solution to the issue, which wouldn't be such an issue if build a little further away. But, it's not, you can't move it, you just need a solution to allow you to get on with your business.
 
That's quite a good idea, it could run along the path halfway between (if that was acceptable to FO) the cabin and the house. Just wondering it it would just have to run as long as the house and not the cabin, if that was so it wouldn't be too bad...but you cant read the Fo's mind, i will put it to my architect. It it was simply the transferance of flame i persume the varnish would surfice but if it's also heat a barrier or water sprinkler system??
I have been unable to source the cost of external sprinkler systems but know they can provide them to whatever standard the FO decrees.
Should know more in the next few days.
Thanks for the replies, Sonya
 
All you need to remember is that fire protection in a building is about delaying the spread of flame & smoke long enough to evacuate occupants safely, half hour in a home 1 hour in a commercial premises. It is not about stopping a fire, that is the job of the fire brigade.

Sprinkler systems, fire extinguishers will put out a small fire or delay the big problem as above.

Varnishes and intumescent paints are about delaying the combustion of the item, steel beam whatever, to delay structural collapse.

The wall along the cabin will serve this purpose and should be satisfactory.
 
Good news, got my fire safety compliance, the officer has accepted the fire retardent with cetificate from contractor on completion. So definetly worth thinking ouside the box and dscussing viable alternatives. Thank to all for their help and advice.
 
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