space between fire door frame and opening

[Guest michael]

We are required to fill the gap between the inner and outer door frame , the inner door frame being  part of the fire-rated door system , the outer being a timber frame around the opening in the concrete or brickwork which are installed by the builder.

Shop drawings show maximum gap allowed as 10mm and intumescent foam literature says to apply between 10mm to 20mm .

 

No problem with that . the problem is that sometimes we have gaps of 3 to 5mm and we cant get the intumescent foam into such a tight gap .

Are we still required to fill these narrow gaps even though they are behind the architrave ? 

Some are saying if the gap is narrow and is filled by timber frame then this is ok and no need to fill.

[AnthonyB]

Most cheaper off the shelf FR foams are not tested for use in frames regardless of the claims on product literature, loads of places have had to rip this out and start again or if lucky been able to trim it down and suitable mastic or plaster over it.

Search for Blue 60 a foam specifically intended to serve your purpose

[Tom Sutton]

Check out Guidance on Fire Door Installation may help.

[Neil Ashdown MAFDI]

Hi Michael,

Because gap sizes can vary so much you may have to use more than one fire stopping method.  First of all, I should say that this subject is dealt with in detail by 'BS 8214:2016 Timber based fire door assemblies Code of practice'.

Generally, for gaps up to 15mm you should completely fill the gap to the full depth of the door frame with tightly packed mineral wool. Make allowance though for a 10mm deep capping of intumescent acryilic sealant on both sides. The sealant should cap the mineral wool for a 10mm depth between the frame and the wall and not just to cover the surface of the gap. Intumescents are gap fillers and need surfaces to expand against under pressure, if applied to just a flat open surface they will just foam and fall away so they need to be inside the gap. 

This should be done all around the door frame to wall gap on both sides.

Where the gap is up to 20mm, follow the same method as above but use tightly fitted 15mm timber or MDF architraves to overlap both frame and wall by at least 15mm. For small gaps such as 3mm to 6mm where use of mineral wool is impractical you should fill the gap as deep as is practically possible with intumescent acrylic sealant. 

For especially large gaps line the opening with continuous solid timber and fill any remaining gaps as above.

Blue 60 is a new-ish product specially for timber fire door frames but minimum and maximum gaps apply to its use and the dedicated packers supplied with the foam must be used.  So use in accordance with the product data sheet.

Hope this helps. 

[Guest Gbb]

Hi. If fitting a new fame into a brickwork opening and there is a gap of say 30mm either side. Would it be ok to use fire rated foam or can I use fire rated plaster. Any answers greatly received 

 

[AnthonyB]

LABC usually require fire grade Rockwool stuffing suitably sealed in, there is also an intumescent foam designed for frames called Blue 60, which if used within manufacturers instructions and parameters will also suit.

Pink aerosol fire foam is a waste of time as it doesn't work for 99% of the things people ignorantly use it for - it's actually only tested and OK for a very finite number of situations, usually very narrow and deep linear gaps between a concrete wall & floor slab and not much else (regardless of the complete fantasy on most cans and supplier websites) 

[Neil ashdown]

The requirements for sealing the gap between the fire door frame and surrounding wall are set out in 'BS 8214:2016 Timber-based fire door assemblies: Code of practice'  https://shop.bsigroup.com/ProductDetail/?pid=000000000030332501 

[Guest FD30s]

Does the gap between the frame and substrate require sealant if there is an architrave already installed. this is when the internal door has already been installed.

[Neil ashdown]

Yes. The architrave should not be relied upon to provide fire resistance.

[Guest Guest SC]

Hello,

I have a question regarding the fire door frame fitting? The instructions state that mineral wool be used to pack out the door frame gap up to 20mm. My gap varies between 10 and 15mm.

Can timber packers be used to secure the frame and then mineral wool be pushed in around the packing? I can't imagine getting a secure enough fixing using the mineral wool alone.

If so should the wood packers be full frame width? Or cut down to mut the wool and sealant around them.

Help very much appreciated as the suppliers technical help is lacking!

[Neil ashdown]

Yes, timber packers should be used at all fixing points so that you can get a secure fixing. They can be full width of the door frame.  Ensure the mineral wool is tightly packed to fill all gaps and leave no voids then cap the wool on both sides with a 10mm depth of intumescent mastic.

[Guest Lee]

Can I use batt behind a door frame where the gap is 15mm to 20mm then intumescent mastic?

[Neil ashdown]

Refer to BS 8214:2016 Timber-based fire door assemblies - Code of practice for details about how to seal the gap. 

 

[Guest Bob]

Hi there. 

I have a large number of F60 doors which need fitting to the clients specification. That is every door needs an acoustic/ fire sealant between the frame and the opening. The packers also need to be F60 spec. Unfortunately the only product on the market we have found is the Blue 60 packers which have only been tested with the Blue 60 foam. I can used hardwood wedges with a fire rated sealent however what I can't do is use the thosands of pounds worth of blue 60 PACKERS we have on site as it hasn't been tested if we include the sealent into mix Do you have a suggestion for the way forward? 

[AnthonyB]

Yes - use Blue 60 foam? Why can't you?

[Bob]

I can't because the architects have specifically asked for acoustic fire sealant between the frame and the openings. And since the combination has not been lab tested if would fail to get certified. 

[Neil ashdown]

So the issue appears to be certification of the work.

Normal practice would be to completely and tightly pack the gap with mineral fibre and then seal to a 10mm min depth to both sides with the Fire Acoustic Sealant. Refer to BS 8214:2016 for minimum requirements. 

If the architect will not allow the use of Blue 60 and the dedicated packers in place of the sealant/fibre combination, then you have two options:

1) Ask the Blue 60 manufacturers what evidence of fire performance is available for use of Blue 60 in full accordance with the fire test evidence but with an additional depth of Fire Acoustic Sealant to both sides. Note, we are saying 'in full accordance' so that the sealant is an extra-over to the fire stopping requirements. Clearly door frame material type, depth of foam and gap size is a major factor here.

2) Use mineral fibre and fire acoustic sealant in accordance with BS 8214:2016.

[Guest Alex]

what are your thoughts on using the mastic for the full depth of the joint in place of the BS 8214 recommended mineral wool with mastic capping arrangement?

This is for gaps up to 20mm where the doors have suitable architraves.

[Neil ashdown]

Does the fire resistance performance test evidence for the mastic product support that use?

[Guest Ian McGee]

BS 8214 notes

9.4.1 General
In order to maintain the fire resistance of a fire-resisting wall or partition when fitted with a door assembly, the sealing between timber-based door frames and the supporting construction should be in accordance with Table 2 to Table 5 as appropriate for the fire performance required.

But is this the fire resistance for the door ie 30min or the fire resistance of the wall ie 60min

i have the doors fire certificate which refers back to BS 8214 and none of the tables show fire resistance of the gap, just the door performance

[Tom Sutton]

Have you checked the manufacturers fire door test report if in doubt go for the highest level. 

[Neil ashdown]

In terms of the requirements of BS 8214 the fire rating applies to the door.

[Guest Jacob Middleton]

Good morning all,

I'm working on a building with alot of traffic throughout the day, The doors are fairly new and most if not all are retrofitted to old frames, the gaps between the frame and wall mainly on the head exceeds over 30mm

I have been asked to fill theses gaps with blue60 and then intumescent sealant, I know that the maximum gap is 20mm, the client is the one that asked for this to be done, should I go ahead with job or should I say I'm not doing it and the doors with the gaps over 20mm needs to be replaced which is the right way to go 

 

[Neil ashdown]

The max gap depends on the sealing method employed.  Contact the product distributor to find out the max gap/min depth and suitable substrates for the Blue60 system  https://blue-60.co.uk/ 

[Guest Matt]

Hi, what is the best way to infill gaps of 40/50mm around an existing door frame?