airtightness of doors with level thresholds

[acresswell]

Anyone got any advice on how to make extra-wide doors as airtight as possible with a level threshold? How good are brush seals at giving an airtight seal?

A bit of background: 
We're about to demolish our house and re-build... plans are in for planning permission (please cross your fingers)

We'll have a log gasification boiler which will obviously require logs. The logs will need to come in through an external door to get into the mud room, then through an internal door that leads to the boiler room.  Both doors will need to be extra-wide to allow passage of a wheelbarrow (I've no desire to lug each log individually from the outside log store to the boiler). 

We're going to incorporate MVHR, so the external door will need to be as airtight as possible.  The door between boiler and mud room will also need to be as airtight as possible because the boiler room will have a huge vent to allow fresh air in to the boiler (there's no such thing as a room-sealed log gasification boiler).  The airtight doors I've found by googling have had a rubber seal mounted in the floor, but that seems a bad idea because the wheelbarrow wheel will wreck it in no time.

Any suggestions?

Thanks

[Justme]

What about a rise & fall seal mounted on the door base?

[biff]

there is a type of hinge that when you close a door the hinge drops the door down 25mm and vise versa when you open it. so you could have a flat 50mmwide rubber seal on the ground with the door resting on it. you could have a rebate on the top of the door as well as the door frame.
      i always regarded these hinges as a last resort,they look quite ugly but they do the job.
                                              biff

[desperate]

Hallo acresswell,

Do you really need a level threshold? I use one of those narrow barrows, the type concrete trucks use, with a proper builders inflateable tyre on it, and it goes over the standard 6*2 cill with a metal weather bar in it no trouble, and being narrow it goes through a 2'6" door.

Desperate

[guydewdney]

look at disabled access thresholds?

[KLD]

Something like these? <http://www.stormguard.co.uk/products/SillsPartM/m/AM5EX.htm>
Klaus

[Baz]

There are lots of seals 2 or even 3 sealing rubbers onto extruded aluminium threshold plates.
There are also some that lift as the door is opened and drop on closing by as much as an inch.
Never seen a barrow too wide for a standard doorway.

[acresswell]

Thank you for all your fast responses

The threshold doesn't need to be completely level, but I didn't want to end up with a huge lump on the floor like you sometimes see on uPVC frames.
I'm planning on using a 2'9" exterior door, and will make the internal one the same.  I know it's possible to fit a barrow through a 2'6" door (I've measured it and the barrow is 2'2" wide) but since I've got the flexibility, it makes sense to put an extra 3" on the width to avoid any scraped knuckles or paintwork. I'll be doing at least a barrow load a day during the winter.

Justme and GuyDewdney... thank you...  using your keywords I've done a search and found this which seems to fit the bill:
http://www.ironmongerydirect.co.uk/Products/Seals_for_Doors_and_Windows/Threshold_and_Draught_Seals/16816/BDA_Front_Threshold

Biff ... thanks for the suggestion, but I don't think I can use those hinges at the same time as a door closer (and I'd rather like to fit a fire door on the boiler room... I know I'll have to wedge or fix it open while I take the barrow through, but I'll sleep more easily at nights...  )

Klaus... afraid I'd already found that stormguard product and discounted it because the rubber seal is built into the floor, so over time I expect it'll get damaged and leaky

Baz... what you describe sounds even better than the one at ironmongery direct (which only has 1 seal).  Any idea where I can find them?

Thanks again,

Adrian

[acresswell]

Problem solved... 
http://www.exitex.com/Weatherbars/PartInfo.aspx?PartRef=1.01.004.

Thanks for all help,
Adrian

[wookey]

I've spent some time thinking about this as I want to be able to wheel bikes, bins and barrows over the threshold, whilst also making it airtight and thermally efficient. You have discovered exitex who do a very good range of aluminium weatherbars/seals. However their thermal breaks are poor as it's just 10mm of acrylic in a chunk of aluminium. I worked out that a better plan was to put solid weatherbars in the floor cill and have a couple of seals on the bottom of the door. So sealing much like the upper part of the diagram you linked to but scrapping the bottom half which is a bad thermal bridge.

There is a pic in this thread: http://www.greenbuildingforum.co.uk/newforum/account.php?u=1432

[acresswell]

Sorry, Wookey... that link doesn't work for me   

[guydewdney]

Door closer - I bought a closer the other day - admittedly it was for a light door, not a fire door, but it had an interestign feature - if you opened it past 90 degrees, it 'locked' and held the door open - a slight nudge then resumed normal action. Nice feature, as theres no mucking about with wedges / hooks etc - I use it on the door to the dining room (mostly to keep the cats out from pooing in the plant pots  )

[Baz]

This is the drop seal I mentioned.
http://www.astrodraft.com/raven-threshold-seals.html

They do various seals http://www.astrodraft.com click on the pictures.

The site was linked a few weeks ago about draughtproofing windows.

We always had a problem with our back door, when every week a storm would dump a gallon of water on the threshold and the westerly wind then blew it in. I solved it about 25 years ago with a can of expanding foam - who needs two doors in a house anyway!

[acresswell]

Thanks, Baz

[CWatters]

Problem solved... 
http://www.exitex.com/Weatherbars/PartInfo.aspx?PartRef=1.01.004.

Thanks for all help,
Adrian

On it's own that doesn't appear to meet part M of the Building Regulations for a new house because there is a 27mm(?) step. Part M only allows a smaller step of around 15mm. You might get away with it but if the BCO is fussy some form of mini ramp would be required. 

These people make an insulated level access entry threshold which looks interesting but I've not used one..

http://www.nevko.com/pages/nevko_external.htm