Minimum height of kitchen wall units either side of hob

[kingandy2nd]

Hi all,

Done a few searches on the forum re the above and have gathered that the minimum clearance is 450mm to the bottom of the wall units (or pelmet if fitted) that are adjacent to a gas hob.

However, what I’m not clear on is where is the starting point for the measurement? Is it the height from the worktop surface or the top of the burners on the hob?

I know the difference is generally not very much, but I have a low kitchen ceiling so every cm counts

Thanks

 

[Agile]

The exact figures should be taken from the manufacturers instructions and are often about 760 mm.

What catches many installations is that some manufacturers want the minimum clear height to extend to a distance to either side of the hob i.e. not just the exact width of the hob!

If the manufacturer does not give dimensions than a CORGI would expect 760 mm above to extend to an extra 50 mm at the back and sides!

Tony

 

[kingandy2nd]

Hi Tony,

Thanks for your reply.

I was looking for the measuring point – is it the top of the hob or the top of the work surface?

I thought the 760mm clearance is to applied to the area directly above the hob (where a 600mm wide cooker hood will go), not the wall cupboards either side of the hob. I thought it was 450mm?!?

However, I’m a little concerned now though as I may have been caught out too . I had wanted my wall units to meet the cooker hood on either side. It’s going to look rubbish if I have to leave a 50mm gap either side of the cooker hood to satisfy the hob manufacturer/Corgi.

I’ve not opened the hob pack to look at the instructions yet as I was going to leave it sealed until I got a Corgi into fit it – thought it would keep it dust free and all the bits together. I’d been working off the dimensions spec’d on the cooker hood. Will have to check the instructions tonight and see.

 

[Agile]

If its a conscientious CORGI he will not be willing to fit the hob at all if you have obstructed the areas above and to the side of the hob.

The reference point is probably the flat surface the hob is fitted on to and thats what is usually shown on dimensioned drawings but only your own hob's instructions should be followed.

Be aware that many CORGI's who do Certificates for landlords assume those default dimensions I have given as they will not have the instructions for individual hobs. Most are pretty much the same anyway.

Tony

 

[kingandy2nd]

Thanks again. I will check the manufacture’s instructions tonight. However, I did read this previous diynot forum post

The installation of domestic gas cookers – New British Standard

Feedback from kitchen designers and installers indicated that there has always been a problem with maintaining the combustible free zone around a cooking appliance. For hobs, this now takes the form of an inverted ‘T’

The reason for this change is that, for example, where a 600mm wide appliance was installed in conjunction with a cooker hood, the hood itself would also be 600mm wide. If the guidance in the previous standard was followed correctly, a gap of 50mm should have been left between the cooker hood and any wall unit on either side.

The new guidance still has this 50mm requirement measured from either side of the hob, but this now only extends up to a height of 460mm. This then allows a cooker hood to be fitted at a minimum height of 760mm (unless stated otherwise by either the appliance manufacturer or the hood manufacturer), but the hood needs to be the same width as the appliance being installed (i.e. 700mm wide hob, 700mm wide cooker hood).

Is this posting incorrect or now out of date? If the above is correct I wouldn’t have a problem with my intended plan.

 

[HPsauce]

Is this posting incorrect or now out of date? If the above is correct I wouldn’t have a problem with my intended plan.

I know this is an old thread but I have a similar problem and have hunted high and low to find an answer.

I need to replace an old hob which is physically 760mm wide overall (including the edging trim) but the right hand section is the controls so the left 580mm or so is effectively a normal 4-burner gas hob. The burners are located centrally under a normal 600mm extractor fan the lower surface of which is 760mm above the worktop, so that should be OK.

Above the controls section there is nothing apart from the ceiling some 1.8m above (that area is in front of a window). Yet a fitter has told us that if we replace the hob with a same-width modern unit (probably a 5-burner design) we must have an extractor fan the same width, going across the window. This is surely insane!
My understanding is that, as the kitchen is around 30 cubic metres volume and has 3 opening windows no ventilation is required anyway.

The other problem is to the left of the hob. Ideally we'd like a replacement to fit straight in without cutting the worktop significantly or, worse, having any "filler" covering strips even if they're just stainless steel.
To the left is a wall unit that comes down to 440mm above the work surface, lower if you include the lighting pelmet (no light so it can go if required). This unit is vertically only 20mm to the left of the outer trim of the existing hob so technically would appear to just infringe the "exclusion zone".

This has all been installed for about 30 years and works fine - with no heating or scorching of the units whatsoever. The units realistically are not going to be moved (tiling etc.) so what am I going to have to do, apart from obviously find a good local Gas Safe person to do the work?
1. On the left, will I have to resign myself to a 50mm clearance and have a small filler strip?
2. On the right can I go out beyond the extractor hood in front of the window or must I buy a narrower hob (around 500mm) and fill the big gap in the work surface somehow?

Any and all comments welcome.

 

[Agile]

Gas regs are intended to be complied with and its not up to an installer to choose to ignore them "because its worked like that for 30 years" or that "there is no scorching".

Its up to you to either do it according to the regulations or to find a nupty installer who not know about or bother with the regulations.

Tony

 

[HPsauce]

Gas regs are intended to be complied with

I'm well aware of that, which is why I asked the questions as to what they are and what they mean in my situation. As I had already said I intend to use a proper Gas Safe installer, your reply implied that I'm trying to get round the regulations which I most definitely am not.

Thanks for your reply but it doesn't actually take me any further forward.

Is there anyone there who does know the regs and can explain how it affects my existing layout please and what it implies for any replacement?

To reiterate:
1. On the left, will I have to resign myself to a 50mm clearance and have a small filler strip?
2. On the right can I go out beyond the extractor hood in front of the window or must I buy a narrower hob (around 500mm) and fill the big gap in the work surface somehow?
Thank you for looking.

 

[Agile]

The regulations now are as quoted on the 22 May above.

Depending on the building, there may also be a requirement for a flame failure device on the new hob.

Of course your registered installer should be able to advice you on meeting the regulations.

Tony

 

[HPsauce]

Thanks, at the moment I'm just trying to find out (for the benefit of my wife) what options we have.

So, as I read it:
1. The wall unit to the left is 20mm too low so the hob need to be relocated/replaced to be 50mm to the right of it, requiring a filler strip.
2. Regarding extending the hob burners in front of the window is this a problem or not? (it's a 30 cubic metre kitchen on the fround floor of a conventional detached house)

 

[Agile]

If its detached then you dont have to have a flame failure device although its advisable.

Tony

 

[HPsauce]

Yes thanks, I understand what an FFD is and would obviously prefer to have one.

Can anyone comment on whether a hob that is partly in front of a wall under a high unit (clearance more than 760mm) and partly in front of a window actually needs any extractor fan in a 30 cubic metre kitchen with 3 openable windows.

And if it does need a fan must its coverage be as wide as the hob. If so can a funnel-shaped hood (wider at the bottom than top) be used to channel fumes?

Presumably a non-combustible hood (e.g. metal) can come lower than 760mm as long as the main extractor unit is above that?

 

[HPsauce]

Just to close my part of this thread down I managed to narrow down the choice of hobs to just a handful and then found copies of the installation instructions online.

I reviewed these (they do include very specific clearance dimensions) with my chosen GasSafe fitter and he confirmed that several of the possible models could be fitted safely and within the regulations without major surgery to the worktop or units.

We made our choice, placed the order and the fitter rechecked the supplied paper manual (same as online) and installed it neatly within the requirements of the regulations and installation manual.

Just for interest it's a 5-burner, 75cm wide unit with FFD on all burners and works very well. The only modifications required were a slight forward extension to the worktop cutout.

 

[Agile]

Its nice to read that someone has bought a good quality unit and had it fitted by an RGI all in accordance with the requirements!

For the record as no one answered you prior question.

There is no need for any extract fan in a kitchen with openable windows. But an extract hood venting to the outside is very useful to control cooking smells and prevent condensation.

Tony

 

[spada01]

Its nice to read that someone has bought a good quality unit and had it fitted by an RGI all in accordance with the requirements!

For the record as no one answered you prior question.

There is no need for any extract fan in a kitchen with openable windows. But an extract hood venting to the outside is very useful to control cooking smells and prevent condensation.

Tony

Presumably okay for existing kitchens, but for a new build property or kitchen in a new location, you would need mechanical extraction. Building Control will not sign off otherwise.