Aluminium Sliding Doors, Flush threshold internally

[GoodDIYjob]

We are soon to do a rear single storey extension, across rear of property.

Looking at doors we had designed in BiFold type doors but now thinking three panel slider maybe better. Anyway the same issue is likely to exist with both.

The door cross section in the designers plans shows a big threshold upstand above inside floor level.

I had taken measurements from the bottom of this diagram to be 2200mm in height.

So now when I look at ordering doors, most say an internal level threshold can be done, just build up the Floor Height.

But I can't just add extra screed height to fill up the threshold. It would mean loosing the equivalent ceiling height and also, then floor levels will not match up with the existing house.

So, unless I am completely misunderstanding, it sounds like I need to order a 2200mm height plus the height of the Door Threshold and Cill height. So Probably 2265-2275 depending on Door manufactuer chosen (all manfuctures I have spoken to say their height include threshold depth). Plus get the designer to change that detail in the section drawing?

What happens if the extra height of the rebate and cill exceeds screed depth of 65mm. Which is seems it may do. Is it the height of the blockwork and brickwork under the door aperture that need to be set lower?

Floor finish may help slightly but if using Karndean or similar it is very thin so doesn't change much..

Appreciate if you could confirm I am thinking correctly or setting me on the right path. if I want a flush threshold I must order extra height to cover the hidden threshold and Cill??



Many thanks

 

[tomfe]

You just have the blockwork/brick work lower than your finished floor level by the threshold height.
If you want the door to appear 2200 high then yes you'll have to add the depth of the cill onto the door height.

 

[GoodDIYjob]

You just have the blockwork/brick work lower than your finished floor level by the threshold height.
If you want the door to appear 2200 high then yes you'll have to add the depth of the cill onto the door height.
View attachment 135396

Yes, thanks.

So yes, I think I am thinking properly now with that section diagram.

But in my case the USB Steel overhead marking the top of the door aperture, can't come down any lower to fill the gap without creating other issues, like then having a downstand into the room, due to another connecting steel running to the centre of the one over the Door.

So I think the answer is the brickwork needs to be set lower by (threshold + cill) height (of any particular door chosen) and also, in terms of height the door needs to be ordered as visible height plus Threshold and Cill (both of which are below finished floor level).

So likely I need to add another 60 - 75mm onto the 2200mm height I was original quoting but depends on exact door and floor coverings? Have I got that right now?

Thanks v much.

 

[tomfe]

Yes
Your measurements sound logical.
Normal door profiles are 2.4 in length so 2275mm would not normally effect the price too much.
You could wait until you have the hole and measure it if you are worried.

 

[John D v2.0]

Just explain to the technical team (not the sales) at the window company exactly what you want and make it clear which dimensions you are supplying. They will know the sizes of all the sections so can match it all up.
The only spanner in the works we had was the window has a maximum height and width due to the strength of the hinges and the weight of the glass, and we needed a couple's of cm more.