Joist spans and supporting walls

woj101

I'm looking to take out an archway wall in my kitchen. All the internal walls of the house are timber-stud. It is a small detached house, seemingly built quite cheaply in 1990.

I've just discovered that floor joists for the first-floor run across (perpendicular / at right-angles) to the wall I was going to take out.

Everyone who's looked at it so far is fairly certain the wall is not a supporting wall, but I'm not yet convinced.

I've looked at the Building Regs maximum clear spans for timber joists and am even more confused. I haven't got definite dimensions of the joists but they appear to be around 90mm deep and are spaced about 400mm apart. I don't how wide they are but am assuming it's the bog standard 37mm.

According to the building regs tables the maximum span is therefore about 1.74m.

But in my lounge I'm pretty sure the joists above run from front to back without any support - about 4.4m.

The kitchen is the same length as the lounge so why should one side of the house need a supporting wall but not the other and how have I got joists over x2 the max laid out in the building regs?

Am I missing something?

Any input or guidance on this will be very much appreciated as I was going to start taking the wall out tonight.

Thank you

mkaibear

woj101 wrote: »

Any input or guidance on this will be very much appreciated

Get a professional in. Something doesn't quite add up and you need to be sure before you start taking walls out!

aliasojo

woj101 wrote: »

Everyone who's looked at it so far is fairly certain the wall is not a supporting wall, but I'm not yet convinced.

Any input or guidance on this will be very much appreciated as I was going to start taking the wall out tonight.

Who is 'everyone'? Are there any professionals involved or is it just your mates?

You'd be daft to start removing walls you are not absolutely certain are not load bearing.

Get proper advice.

Neighbour removed a partition (stud/plasterboard) as friends had done theirs and said it was ok. Surveyor called out after the event said they were lucky the house did not collapse on them, they got away with movement and cracking.

MX5huggy

Your floor joists will not be 90mm deep, 225 or 250 would be more typical you can see the depth normally where the stairs are.

iamcornholio

woj101 wrote: »

Any input or guidance on this

as I was going to start taking the wall out tonight.

Yes ... wear a hard hat.

Your floor joists are not going to be 90mm deep, as stated, so you need to remeasure them

It is rare for timber stud walls in modern housing to be load bearing, but that is not to say that yours is not.

If you can't be sure, then you need to get hold of someone you can be sure, to look at the arrangement

aliasojo

iamcornholio wrote: »

It is rare for timber stud walls in modern housing to be load bearing, but that is not to say that yours is not.

If you can't be sure, then you need to get hold of someone you can be sure, to look at the arrangement

Mine are. House was built in the 70's, not sure if that's classed as modern or not.

ormus

http://www.carryduffdesigns.co.uk/technical/floor-joists.html

a standard 8x2 imperial joist will span 4.3 m.
at 400mm centres.

woj101

In my defense, these were very quick measurements through a small hole in the floorboard...

Turns out I must have glanced at the inches side of my tape measure but assumed centimetres because 90mm appeared so prominently in the Building Regs tables.

So my joists are in fact 9 (or almost) inches deep. They're also about 60mm wide. Just checked the building regs tables again: 63mm x 220mm support a span of up to 4.91m. The room is about 4.7m.

All this is quite a relief to find out this evening because as it happens I started taking the wall out on Friday and have all but finished the job today!

I figured if the lounge ceiling was alright unsupported then the kitchen must be too.

Plus, I did take the advice of my Dad (a surveyor) and one builder, one carpenter, two electricians and a D&T Teacher.

aliasojo

woj101 wrote: »

Plus, I did take the advice of my Dad (a surveyor) and one builder, one carpenter, two electricians and a D&T Teacher.

Yet you ask for advice from faceless strangers on the internet who may or may not know what they are talking about? Each to their own I guess.

woj101

Well what none of them were giving me were any cast iron reasons why it would be ok. I figured if I could make sure it complied with Building Regs it would be fine. My issue was with how I was interpreting the Building Regs tables (or so I thought) but thanks to the responses I got here I realised that my hurriedly gathered joist measurements were ridiculously inaccurate.

So this thread was still worthwhile and has helped me reassure my girlfriend that the house won't collapse. Which is nice.

Thanks all.