New build house 3 joists together notch or drill?

[Mgrant]

Hi, I have a 3 floor new build house to first fix that at two places on each floor there are 3 joists but up together. I think due to the staircase. Would/ has any one drilled through with an angled drill 3 joists in a row? Or the other option would be notching But I hear there is strict guildlines to were you can and can't notch? Any advice on this would be helpful, thanks.

 

[stevetheplumber]

les are here Rules for Notching Joists | Joist Notch and Hole Calculator | DIY Doctor and applyt to both holes and joists ive drilled triple joists but its hard work you need a good angle drill and good bits often due to space youll need a short bit to start the a longer one and you may then have to drill from the other side

 

[jldplumb]

Hi, I have a 3 floor new build house to first fix that at two places on each floor there are 3 joists but up together. I think due to the staircase. Would/ has any one drilled through with an angled drill 3 joists in a row? Or the other option would be notching But I hear there is strict guildlines to were you can and can't notch? Any advice on this would be helpful, thanks.

if its a new build you've probably got engineering joist with flanges, you should NEVER notch or cut the flanges, i often drill through 3 sometimes 4 joists together, just need an extension bar for your driver and bit. So drilling is fine just leave double the diameter of the hole size between holes.

 

[Mgrant]

Thanks no they are standard 3inch by 8inch joists. So can be drilled with an angled drilled and extension bits? Is notching un-advised then, would be a pain having to get in before the floor is down.

 

[Mgrant]

How do you get on with the engineering joists if the pre-made knock out holes are a fair bit out? Just bend the plastic?

 

[jldplumb]

How do you get on with the engineering joists if the pre-made knock out holes are a fair bit out? Just bend the plastic?

yea drill them defo, i 1st fix using my 18v combi and auger bits find it quicker than using an angle drill. With regards to pre drilled joists sometimes you can pull a set in your speed fit to tidy it up a bit. Usually the chippys put some joists the wrong way round so some holes are on the other side of the house lol.
also if your getting materials i always go for hep stuff

 

[AWheating]

on the knockout joists you can drill a hole where you want, dont need to use the knock outs marks.
mark the center of your next hole 3x dia of largest hole away from each other on standard joists and stick to the 0.25-0.4 drill zone in the center and you will be fine.
wastes pipes should not be drilled through the joists.

notching is fine on standard joists if it the correct zone, but not done on most new builds now as its not suited to plastic pipe work and flooring is glued down, gets damaged when lifted and its takes ages to battern and refit the floor afterwards.

 

[Mgrant]

on the knockout joists you can drill a hole where you want, dont need to use the knock outs marks.
mark the center of your next hole 3x dia of largest hole away from each other on standard joists and stick to the 0.25-0.4 drill zone in the center and you will be fine.
wastes pipes should not be drilled through the joists.

notching is fine on standard joists if it the correct zone, but not done on most new builds now as its not suited to plastic pipe work and flooring is glued down, gets damaged when lifted and its takes ages to battern and refit the floor afterwards.

Thanks could you explain the 0.25-0.4 drill zone please?

 

[Mgrant]

do you mean you can drill between 0.25-0.4 of the span of the joist?

 

[kris]

Thanks could you explain the 0.25-0.4 drill zone please?

Have a read of these.

https://www.google.co.uk/url?sa=t&s...Ux9Dxc&usg=AFQjCNHHRERJoynvkf3Z99s3iUKtTDS7-w

 

[kris]

I thought u couldn't bore double or triple joists but I might be wrong. Certainly the site I've recently finished NHBC stipulated that no double joists were to be bored . The NHBC rep let me off as wouldn't have been possible another way . So it's maybe just there stipulation n not a reg.

 

[kozak1968]

Is this info up to date?

les are here Rules for Notching Joists | Joist Notch and Hole Calculator | DIY Doctor and applyt to both holes and joists ive drilled triple joists but its hard work you need a good angle drill and good bits often due to space youll need a short bit to start the a longer one and you may then have to drill from the other side

 

[Mgrant]

I thought u couldn't bore double or triple joists but I might be wrong. Certainly the site I've recently finished NHBC stipulated that no double joists were to be bored . The NHBC rep let me off as wouldn't have been possible another way . So it's maybe just there stipulation n not a reg.

Anyone else heard you can't drill double or triple joists?

 

[Mgrant]

on the knockout joists you can drill a hole where you want, dont need to use the knock outs marks.
mark the center of your next hole 3x dia of largest hole away from each other on standard joists and stick to the 0.25-0.4 drill zone in the center and you will be fine.
wastes pipes should not be drilled through the joists.

notching is fine on standard joists if it the correct zone, but not done on most new builds now as its not suited to plastic pipe work and flooring is glued down, gets damaged when lifted and its takes ages to battern and refit the floor afterwards.

Sure I'd read on the engineered joists that have knock out holes you couldn't drill holes. I'll have to see if I can have a word with one of the inspectors I guess.

 

[Ch4 plumbing]

Sure I'd read on the engineered joists that have knock out holes you couldn't drill holes. I'll have to see if I can have a word with one of the inspectors I guess.

Ask the manufacturer of the joists (prefab) soon let you know what you can/can't do.

 

[Mgrant]

Thanks I will. Has anyone heard as stated above that 3 joists butt up to each other can't be drilled? Is it best of consulting the building inspector before doing any drilling/ notching?

 

[jldplumb]

Thanks I will. Has anyone heard as stated above that 3 joists butt up to each other can't be drilled? Is it best of consulting the building inspector before doing any drilling/ notching?

we've never had any trouble off site managers (taylor wimpey,persimmon,charles church,barrats,gravan, bellway etc) for drilling doubles or triples. only place we've told not drill holes is upright stud clusters on timber frames and the big 10 x 3 (or whatever) joists that bear more load than the others.

 

[Mgrant]

Thanks if the first floor joists sit on supporting wall downstairs does this effect the measurements of the span of the joist?

 

[jldplumb]

Thanks if the first floor joists sit on supporting wall downstairs does this effect the measurements of the span of the joist?

yea it does, the span of a joist is measured from the inside edge to inside edge of its supporting walls

 

[AWheating]

Sure I'd read on the engineered joists that have knock out holes you couldn't drill holes. I'll have to see if I can have a word with one of the inspectors I guess.

You can run soil and ducting through them if you need but always check the manufacturers guides.

 

[AWheating]

Thanks I will. Has anyone heard as stated above that 3 joists butt up to each other can't be drilled? Is it best of consulting the building inspector before doing any drilling/ notching?

normally ok to do, but if theres somebody to ask then best to do so, especially on timber framed.