level access and dpm

[LSB]

I've had a bad night stressing about DPM, level threshold and BC.

 

In our family room to the garden I want 2 level threshold doors, that's the easy bit.

When I say level, I don't want to go to a slope or ramp, I want it to be level to the whole outside patio / garden for a wheelchair user to be able to go from inside to out without rolling away and then struggling to get back in.

Terrible drawing below.

The bit going down is the drain, the bit going up is the door.

 

 

But, the DPM must be 150 above GGL ????

 

So, do we just do this which doesn't have the DPM 150 up, or is that covered by the drain.

 

 

 

I've looked at our SE drawings, books, interweb and nothing explains how it meets the latest building regs.  All our drawings were pre the BC change.

I have a drawing which shows it from side on, but that doesn't cover the above question.

I don't have any level thresh-hold in our current house and all the doors are steps to get in, too old for ramps or anything.

 

We spoke to a guy last week who sells level thresh-hold drains and bizarrely he said, you can't do this in the UK, so why did he have a stand at an exhibition !!!

 

We haven't finalised on our window / door supplier yet, we know the sizes, positions etc just not the finer details.

 

By the way, this is French doors, not sliding or bifold, just 2 pairs of opening doors.

 

 

Edited May 12, 2023 by LSB

[The Reverend]

The difficulty you will have is pooling, creep and wind driven rain. A common practice is to use a ramp up to a plateau and then cross the thresh-hold, see your local council flats entrance.

I'm going to face the same issue but hoping a french drain in front of the doors will solve the 150mm issue.

 

[The Reverend]

This may help

https://www.labcwarranty.co.uk/technical-blog/a-step-by-step-guide-to-level-thresholds

 

[LSB]

3 minutes ago, The Reverend said:

The difficulty you will have is pooling, creep and wind driven rain. A common practice is to use a ramp up to a plateau and then cross the thresh-hold, see your local council flats entrance.

I'm going to face the same issue but hoping a french drain in front of the doors will solve the 150mm issue.

 

I really don't want one of those horrid ramp things, I would rather slope the whole patio, but then I have the worry about my disabled visitors disappearing into the garden unable to return 🙂

I also hope the drain will work, but at the moment I'm struggling to get a definitive answer.

I've just had the builder, who's not had to do this before, asking what he should do.

At the moment I've just said to leave the gap where the doors will go.

 

[LSB]

1 minute ago, The Reverend said:

This may help

https://www.labcwarranty.co.uk/technical-blog/a-step-by-step-guide-to-level-thresholds

 

thanks, I've got a few of these drawings, but none of them cover what you do with the DPM which runs along the top of the foundation blocks.

This is as per my 2nd terrible drawing.

[The Reverend]

For the UK it would be 150mm I think but LABC says 125mm

 

 

[joe90]

@LSB I did exactly as your lower drawing, (DPM dips under door frame) the patio slopes slightly to help rain run off and prevent puddling, and no drain, even with driving rain no problem.

[Temp]

The DPM/DPC is meant to be 150mm above ground level to prevent rain splashing up above it. If you find another way to prevent it splashing it should be OK. Some people put a channel filled with gravel.  

 

Lots of example photos in here..

 

https://www.pavingexpert.com/splash_strips

Edited May 12, 2023 by Temp

[Temp]

Or do have the DPC 150mm up except at the door itself.

[joe90]

9 minutes ago, Temp said:

Or do have the DPC 150mm up except at the door itself.

That’s what I said above (and done) 👍

[Dave Jones]

what you need is a vertical DPC. This is a cavity tray that allows you to 'move' the dpc higher up the wall. This allows a fully level threshold (with a suitable cill) and not having to worry about the normal 150mm limit. Same is used where you are building against sloping ground and need to protect the 'upslope' wall.

 

Unless of course its a front door and they are automatically immune to the 150mm rule !!

 

We have done this for every build as it costs peanuts and gives total flexibility.

 

The example here moves DPC 225mm higher than normal.

 

 

 

 

 

 

[LSB]

14 hours ago, Temp said:

Or do have the DPC 150mm up except at the door itself.

it's only at the doors that I want lower, I want 4 x level threshold French doors along a long wall

 

[Radian]

22 hours ago, Temp said:

The DPM/DPC is meant to be 150mm above ground level to prevent rain splashing up above it. If you find another way to prevent it splashing it should be OK. Some people put a channel filled with gravel. 

As I've pointed out before, doors are inherently splash-proof so the requirement is different to masonry. I.e. non-existent.

The real issue is how well the door and casing can resist wind-driven rain. Sliding doors are excellent in this regard as they run in a recessed, drained, channel.

[Dave Jones]

what we did on our 7m bifold, we hard a normal 170mm cill on it which provides the drip detail for the doors then slabbed over the cill with porcelain, we put pea gravel under the cill to support and provide drainage. No need for any linear drains and nothing to worry about with splashing etc.

 

Had no problems with it at all, the frame free drains as it should.

[LSB]

1 hour ago, Dave Jones said:

what we did on our 7m bifold, we hard a normal 170mm cill on it which provides the drip detail for the doors then slabbed over the cill with porcelain, we put pea gravel under the cill to support and provide drainage. No need for any linear drains and nothing to worry about with splashing etc.

 

Had no problems with it at all, the frame free drains as it should.

we are planning on 4 sets of French doors rather than bifold or sliding, as a barn conversion planning says that it needs to look like opening for internal areas.

We looked at some alu and upvc ones yesterday, but the salesman could show us one, but didn't really understand how they were installed.

 

[Dave Jones]

need to make sure you have the vertical tray installed first on the walls. 

[LSB]

9 minutes ago, Dave Jones said:

need to make sure you have the vertical tray installed first on the walls. 

what is one of those - help

 

[Dave Jones]

drew you a picture 2 posts up

[LSB]

4 minutes ago, Dave Jones said:

drew you a picture 2 posts up

of course, thanks, head exploding with all the questions I have to answer.