Fire door frame hinge position

[whatsthenews]

Hi,
We need a fire door between our newly insulated/boarded utility room and garage.
We've got this Wickes fire door frame which is 108 mm deep.

Can someone confirm whether the hinges fix on the edge nearest to the rebate for the intumescent strip, so that the spine of the door sits over the top of the strip when in the closed position? This means 25mm S/S ball bearing hinges overlap onto the groove for the strip, so presumably you have to take the rebate for the hinge down to the depth of the groove for the intumescent strip, which is 4mm.The hinges are 2mm thick.

If the hinges were fixed on the other edge, then the intumescent strip would be on the far side of the door stop, so on the protected room side of the door? Assume that the idea is that the strip expands as possible if there's a fire, ie positioned closer to the fire risk area?

 

[Deleted member 174758]

The intumescent strip must run down the centre line of the door edge either i the xasing or in the door and most are 4mm deep. The hinges are set into recesses in the edge of the door, but the intumescent strip, when fitted to the door) is broken at the points where the hinge recesses are. Your hinges need to be fire rated, which generally means stainless steel or in some cases brass. Most fire hinges I have dealt with are designed to accommodate a door with a 3mm gap around 3 sides. The hinge leaf thicknesses is generally something between 2 and 3mm. Don't take the recesses down to 4mm - that will cause the hinges to bind and the door will never close. The hinges should be installed with an intumescent hinge pad beneath each (on both door and casing) to give continuous fire integrity and provide a degree of heat insulation for the hinges. The doors may have no less than 2mm and no more than 4mm gap around 3 sides and no more than a 4mm gap at the bottom when the door is closed (unless an automatic intumescent drop seal is fitted which can guarantee this).

In addition closers, locks, keeps, etc are supposed to be thermally isolated in the event of a fire and need either something like Intregraf intumescent paper wrapping or a bed of intumescent mastic beneath them.

Don't forget that there are regulations about how gappings around the outside of the casing are dealt with - a squirt or foam, or even fire foam, is no longer adequate.

 

[whatsthenews]

The intumescent strip must run down the centre line of the door edge either i the xasing or in the door and most are 4mm deep. The hinges are set into recesses in the edge of the door, but the intumescent strip, when fitted to the door) is broken at the points where the hinge recesses are. Your hinges need to be fire rated, which generally means stainless steel or in some cases brass. Most fire hinges I have dealt with are designed to accommodate a door with a 3mm gap around 3 sides. The hinge leaf thicknesses is generally something between 2 and 3mm. Don't take the recesses down to 4mm - that will cause the hinges to bind and the door will never close. The hinges should be installed with an intumescent hinge pad beneath each (on both door and casing) to give continuous fire integrity and provide a degree of heat insulation for the hinges. The doors may have no less than 2mm and no more than 4mm gap around 3 sides and no more than a 4mm gap at the bottom when the door is closed (unless an automatic intumescent drop seal is fitted which can guarantee this).

In addition closers, locks, keeps, etc are supposed to be thermally isolated in the event of a fire and need either something like Intregraf intumescent paper wrapping or a bed of intumescent mastic beneath them.

Don't forget that there are regulations about how gappings around the outside of the casing are dealt with - a squirt or foam, or even fire foam, is no longer adequate.

Thanks for replying.
The frame (as you can see) has the channel for the IS (we've got the one with brushes as believe it needs to be an FD30S door?)
the issue is that the hinges we have (SS ball bearing fire rated) are 51mm wide (each leaf 20mm) but the width between the edge of the frame and the channel for the intumescent strip is only 15 mm, so the hinge leaf (and one of the screw holes) goes over into the channel.
If we take the recess for the hinge down to only 2 ml, surely the hinge isn't going to "sit" flat, because of the 2 mm difference where it sits across the channel for the strip? The screws are pretty pathetic size 3 and the heads sheer off if you look at them the wrong way.
I've read that intumescent material isn't required behind hinges if the door is in a domestic setting, but having said elsewhere I've read that they are! It's not an issue as long as we know-we've got a sheet of the material.
Also got a fire rated self closer and material to wrap around the 5 lever mortice lock.
I think we should be fine re the gaps.

What's acceptable for filling gaps between the casing and brick now? We've got both fire foam and intumescent sealant? Also, are pieces of treated timber /plywood acceptable for shims?

EDITED- we weren't planning on recessing the hinges into the edge of the door by anymore than the depth of the hinge.

 

[Deleted member 174758]

The hinges are recessed to the depth of the hinge leafs. The intumescent strip is cut some that it doesn't pass behind or beneath the hinge. The hinge leaf must be flush to the jamb. This means that there could be a groove beneath the hinge. If so it should be filled with intumescent caulk (fire stopping). If the hinge cuts into an intumescent strip it is normal to scribe the intumescent strip to fit around the hinge

Fire doors are fire doors regardless of whether or not they are commercial or domestic - at least that is what I was taught. The current advice is that hinges should either sit on an intumescent pad or have intumescent caulk applied to the back sides to ensure that a full intumescent seal is achieved.

Packers can be timber, intumescent or plastic still, but must come no nearer than 10mm to the face of the casing or lining (i.e they must be set back behind the architraves). This is to accommodate a 10mm thick layer of intumescent caulk between the main gap filling material and the back face of the architrave (one side of the door only for 30 minutes, both sides for 60 minutes). Gaps between casing and masonry/wall wider than 10mm should be packed with mineral wool, less than 10mm they should be filled with intumescent caulk. There is now concern over the ong term durability and effectiveness of AFFF (fire) foam as it has been shown to have failed in a number of fires. On commercial jobs its' use is sometimes only sanctioned after a controlled burn test of a sample door and casing.

BTW there's aren't new - many became in a long ago as 2005. It's events like Grenfell which have spurred mainly the insurers int action

 

[whatsthenews]

Thanks again.
That all makes perfect sense.
The paragraph " Packers can be ........" and then further on "gaps between ....."
We only have the gap between the fire door frame and the masonry which is bigger than 10mm on the side where we fixed to the edge of the dividing wall (uneven brick work)
Re Grenfell-just prior to the fire we were living in a Newcastle council owned 6 storey block. 60's built non traditional concrete construction. External covered communal balcony access to individual flats. Lots of "discussions" with the ALMO who managed on behalf of the council re fire and asbestos safety. There was no way on this earth that the compartmentation in that block was intact. In 6 months we had 3 fireson our floor, one of which was an arson attack of a letterbox using accelerant. Above the front doors, running the full length of the balcony ceiling there was a plywood box containing all the com's cabling, including the one for the centralised smoke alarm/intercom system. No fire breaks. They told me that the doors labelled Fire Door into the stairwell weren't fire doors and the stairwell didn't need to be protected as the external balconies were classed as "relative safety".

 

[Deleted member 174758]

Where you have fixed directly to the masonry if there are any gaps at all just fill them with intumescent caulk (there will be gaps - the caulk needs to be pumped in so thay it ideally forms at least 10mm deep bead). Ifneeds be use a spatula or stopping knife to get it in. On the other side the gaps should be packed with mineral wool (Rockwool, Earthwool, etc) and the last 10mm to the surface (on one side only) should be filled with intumescent caulk. The mineral wool is fire resistant, the caulk expands when it gets hot enough to prevent the fire breaching the containment.

 

[whatsthenews]

Where you have fixed directly to the masonry if there are any gaps at all just fill them with intumescent caulk (there will be gaps - the caulk needs to be pumped in so thay it ideally forms at least 10mm deep bead). Ifneeds be use a spatula or stopping knife to get it in. On the other side the gaps should be packed with mineral wool (Rockwool, Earthwool, etc) and the last 10mm to the surface (on one side only) should be filled with intumescent caulk. The mineral wool is fire resistant, the caulk expands when it gets hot enough to prevent the fire breaching the containment.

Brilliant. We have rockwool. Thanks so much for your help.

 

[JohnD]

what's wrong with the fire foam?

edit

I see now.

Maybe I could scrape out the gaps and add caulk. I don't think I have any as big as 10mm

 

[Deleted member 174758]

I did work for a firm a few years ago whose internal standard on narrow gaps was to fill with AFFF foam, scrape out to a depth of 10mm each side and then fill up the last 10mm with intumescent caulk. This was accepted because they had done a burn test with the products which we used and the performance of the system as a whole was proven (bearing in mind that this was in places like courts, council and government offices, hospitals etc - all very public spaces). It's where AFFF is used on its' own with no additional intumescent layer that you cannot guarantee the performance of the fire stopping - with the intumescent caulk you have an effective seal around the casing almost regardless of any deterioration of the foam.