Very interesting indeed. Clearly the various builders, plumbers and electricians that have worked on my house over the past 110 years have failed to watch your video!

Thanks Derek. I've always found this confusing so it's nice to have it explained clearly. Great video. 👍

Thanks a first class explanation. Very clear and broken down into the relevant sections.

Thanks Derek , As always an excellent presentation given with clarity.

You are a real help to engineers specially newly accredited 👍 big respect to you mate and you are actully helping people not make mistakes that could lead to damage and also disasters that could result in people being hurt.

Thank you for your efforts, good video better that so called training centres

Love this video Derek ...seen some rum pipe runs in me life ..cracks me up the way Plumbers lift and relay floor boards...and lets not mention chipboard flooring....LOL.

very informative video

Very informative without banging on forever - Thank you

The last of my 6035 practical assessments 👍👍👍 saved the best to last

Always makes everything clear and easy to understand top guy top trainer 👍🏻

Great video will be sharing its information 👏🏻👏🏻👏🏻👏🏻

Brilliant presentation Derek. Now why do I watch these now I'm retired 😁

Thanks Derek. Informative and essential as ever👍🏾

So - notches are actually in the red zone A for holes. Holes are in the red zone C for notches ! So the 100 mm min distance btwn a hole & notch must straddle these zones.

Great video that helped me with my acs reassessment fantastic

Very good presentation

Absolute legend, have learnt a lot from watching your videos.

Thank you so much i understood it better

Brilliant vid. Thanks Derek!

Hi Derek very interesting. Mark

Thanks Derek great video 👍

Thomas Bradwell Thanks Derek

I've kind of made up my own rules to go along with this. Generally the joist size will be the same size throughout the house regardless of span. They'll probably be sized for the greatest unsupported span found. For example, in my house I've got a 7x2 spanning less than 700mm in one place. Therefore I reckon I've got at least half unnecessary wood. 😅 Only to get me out of trouble. You would probably need a structural engineer to calculate it if you got pulled up. Position is still important because the bending moment of the timber is the same

Great info well done 😊👍🏼♥️

Thank you, Nikola Ditsov

Hi there Derek thanks for the video... brilliant as usual!! currently in my niceic book I think some things have started to become a bit misleading... fig 5.47 says that the max hole is equal to and no greater than 0.30 (30%)of the depth - and if that is the case then with the example they give marked in red ...then using a 200mm joist the max hole size should not be more than 60mm however the book says 30mm ....!! also in the same fig it says the min distance is equal to and no greater than 10%( 0.10) for a hole !!! Arrrggghh ....getting a bit confused .Can you throw any light on this for me ? many thanks again 🙂

Strange. From a structural point of view the bearing end of the joist has maximum shear force and zero bending stress, so the best place to notch. In the centre of the span is maximum bending stress which increases from the centre to the edges. So in theory notching near the wall (bearing) would be the best place. However in the centre is the worst place to notch but the best place to drill through is the centre (neutral axis) Of course as you say there's a limit to the size of holes or notches and smooth round edges are best! You can make extra notches of course. Bonus notches, GOODNIGHT! 🤣

Derek you were correct, there's no air in the expansion tank. I've ordered a new one.

When joists from a room meeting those from another room, still in the same direction but touching themselves sideways (usually joined together by bolts, plate with retaining nuts, are they to be considered 1 long joist when talking about 7 and 25%?

What about going through noggins? Does this still apply in full as they are secondary to the main joists. Thanks Brian

renovating my kitchen, plan to run a 3" drain pipe through 5 solid wood joists of 8", (in B area) the holes that run the drain pipe are over 3" Dia, so I want to use the metal joist reinforcement plate to support the joists. it is possible? Thanks

When I take up flooring for plumbing issues I always find the middle red danger zone drilled or notched, 9 think that is because if you refuse to do it, you should go for a very long run instead, is it correct?

thanks derek..

Another interesting video

Can you change normal joist for metal web ones?

Worked on a 16c farm house with oak beams and joists floors . both election and plumber notched and drilled joists much to my objection both within allowed spec but together they structural weakened the floor that could barely support itself it was already bent due to it's age . it was used a office above with filing cabinets after the work the floor began to move and became obvious it had been structural weakened the old timber which had dried out and became less strong over time . eventually the replacement oak floor joists were fitted between floor beams spanning 4ft The regs don't cover all situations and doesn't always give you the OK to go ahead without seeking advice from a structural engineer . Just been to look at another house fitted with none standard joists 9x1 over 5 meter never seen such thin joist used and fitted in the 1800's before any building regs existed chopping these joists would seriously weaken the floor . in this case I would run pipe work behind skirting boards and design bathroom so soil pipe doesn't interfere with floor joists . sometimes you have to design the bathrooms around the existing layout and not to the customers ideas if it structural compromise the floor joists . Also gas flue and solid fuel flues stoves pipes need to kept away from load bearing beams seen so may chopped out below load bearing beam especially 45° flues through solid stone walls these structural weak walls significantly . one customers fitted flue through a supporting 16inch wide column with a window lintel bearing both side and a oak beam 12x12 resting on top between the two windows lintel . the fitter was quite happy to smash a 6inch hole just below the Intels at 45° under a two tonne oak beam . if your unsure always seek advice from a structural engineer if the customers is insisting on a location and your unsure insist on a structural engineer reported before knocking and big holes in joists or walls or below beams.

Thanks Derek this is really helpful. Can you do any video on imperial and matric meters gas rats, reverse gas rate from appliance to meter and reverse gas rate from imperial ft3 to metric m3/hr gas rate thanks.

Thanks 🙏

😂😂 build control would have a feild day in all these old terrace houses

Is this knew builds or retro installs and how many years back does this apply. As I see lots of older properties being drilled a notched in the wrong places. Thanks

One of my pet peeves is plumbers not adhering to this. Some of the joists I’ve seen with 2 inch notches in the centre for bath wastes lol.

Hi Derek great informative videos you make 😊 I'm have a problem with a Schrader valve in an expansion tank. It won't release air when I press the pin in so can't check the pressure. If I try to remove the valve with the removing tool will it shoot out like a bullet? 🙈😄

Can you just increase the joist size in the area that you need to drill/notch by by nailing/bolting a short length of deeper joist?

Thanks Tomkat... read somewhere notches should be U-shaped.... any thoughts.

i need to run a vent hose for my cooker hood if the joists are going the wrong way how can this be achieved? the duct is 100mm. obviously cant drill a 100mm hole in a joist

👍 Sue Warrington

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How do you increase the size of the joist?

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Why we cant notch closer to the support than A ? Please explain

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👍 Shane hunt

tomkat👍

Bryan Williams

Jon-Paul Ward

Stephen Humphreys

Raza watched 08/02/2022

Marcin Masalski

Seen a whole row of joists notched out to carry a 110mm soil pipe.😖😖😖

James O’Brien

A Przybyl

Mike Fahy

Bilal

As much as this is acurate no one measures the joists lol

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