Builders made door opening too small

[plummet]

Hi

Just getting towards the completion of an extension coming off the lounge, and we realised that the door opening between the lounge and the extension is too small, due to a miscalculation by the builder.

The overall result is that the fitted internal 1981mm door has been cut down to 1915mm.

I went along with it last week, but I'm regretting it now as it does look oddly small.

In anticipation of an awkward conversation on Monday, I'm wondering what options the builder has. For example, I wonder if they could simplify the work to increase the opening height by replacing the concrete lintel with a thinner steel lintel?

The width is a few cm short as well.. I think because the sides were dot & dabbed with generous dabs, so hoping that can be resolved by stripping back and using hardwall plaster & skim instead.

Thanks.

 

[johnny2007]

I've never seen such mistake being made, so just to throw it there: does it comply with building regulations?
Others here will know or you could check yourself.
I would do it but I'm busy today and just having a coffee break.

 

[cdbe]

If it's a concrete lintel, they could probably replace it with a single leaf (L shaped) steel lintel, or possibly (depending on any load above, even an internal door lintel:

 

[noseall]

Hi

Just getting towards the completion of an extension coming off the lounge, and we realised that the door opening between the lounge and the extension is too small, due to a miscalculation by the builder.

The overall result is that the fitted internal 1981mm door has been cut down to 1915mm.

I went along with it last week, but I'm regretting it now as it does look oddly small.

In anticipation of an awkward conversation on Monday, I'm wondering what options the builder has. For example, I wonder if they could simplify the work to increase the opening height by replacing the concrete lintel with a thinner steel lintel?

The width is a few cm short as well.. I think because the sides were dot & dabbed with generous dabs, so hoping that can be resolved by stripping back and using hardwall plaster & skim instead.

Thanks.

The door casing/linings are bought off the shelf as proprietary items. Their sizes are already set according to existing door sizes. The door casing head height should be 1981mm+ about another 12mm i.e. 1994mm-ish. The width of the casing will have had the header trenched out to suit either a 838mm wide door or a 762mm door. Everything else is a bodge on behalf of your builder and should be put right, otherwise you will be removing too much material from your doors.

 

[noseall]

As an aside, stud openings or brick-brick openings for a standard 762mm x 1981mm door should be in the realms of 815mm x 2030mmish and never less. The sides are more stringent, but the header or lintel should be sited higher to allow a wee bit of wiggle room.

 

[plummet]

Thanks all. From a quick search I think it isn't a building regs issue, but it's certainly a bodge. We're very keen to get the job finished and get on with carpeting etc., but I think this is too big a compromise and we'd regret living with it so I'm going to have to get them to fix it.

Think that'll be a bit of a job as they'll have to take the lintel up by a course of bricks, so that'll mean repairing the hardwall plastering on the lounge side and the dot & dab on the extension side.. but I guess that's their issue.

 

[Notch7]

Thanks all. From a quick search I think it isn't a building regs issue, but it's certainly a bodge. We're very keen to get the job finished and get on with carpeting etc., but I think this is too big a compromise and we'd regret living with it so I'm going to have to get them to fix it.

Think that'll be a bit of a job as they'll have to take the lintel up by a course of bricks, so that'll mean repairing the hardwall plastering on the lounge side and the dot & dab on the extension side.. but I guess that's their issue.

as its lounge to extension, I’m guessing it was an external wall, so it prob needs 2 lintels.

I bet the builder never set out a datum - I always think it’s best to have a datum of say 1000mm above finished floor level, then everything can be taken off that.

 

[plummet]

as its lounge to extension, I’m guessing it was an external wall, so it prob needs 2 lintels.

I bet the builder never set out a datum - I always think it’s best to have a datum of say 1000mm above finished floor level, then everything can be taken off that.

Yep - you are right on both points.

I did the electrical work (under my electrican brother's supervision) and made a FFL datum by drilling a hole (before the door opening was there) and shining a laser level through it. From what the guy said on Friday, I think they made assumptions based on the height of the DPC and started the opening too low. It's probably why they also ended up needing about 100mm of pumped screed! Still can't quite make sense of it though as that should have been apparent when they knocked through.

 

[noseall]

Yep - you are right on both points.

I did the electrical work (under my electrican brother's supervision) and made a FFL datum by drilling a hole (before the door opening was there) and shining a laser level through it. From what the guy said on Friday, I think they made assumptions based on the height of the DPC and started the opening too low. It's probably why they also ended up needing about 100mm of pumped screed! Still can't quite make sense of it though as that should have been apparent when they knocked through.

Amateurs.

We always remove a small amount of masonry at skirting board level, wherever a knock through occurs, in order to establish FFL. This is done prior to pumping the trench concrete and establishes early on the important finished floor level (FFL). Everything is determined from this. i.e. DPC height and whether it conflicts with floor levels, how we set the hard core level, blinding, insulation and base concrete height. If there are more than one knock-through then we look at them all and set the masonry accordingly.