joist Concern Around Joist Notching/Cutting Works Undertaken

[JRR]

Hi,

 

First time post and I would just be very grateful for some advice please.

 

I have had an extractor fan fitted into the downstairs toilet conversion, which is located in the old cupboard beneath the stairs. The extractor flexible hose then runs up and beneath the floorboards on the landing and into the corner of one of the bedrooms before exiting the front of the house just above the garage. I initially requested that the contractor ran the hose adjacent to the joists and out of the side of the house as this would have meant that none of the joists would need to be disturbed in any way. However, I was shocked to see that the contractor has drilled out a large section of the joist to run the hose out above the garage at the front of the house. Please see the attached photographs. I believe that a depth of approximately 60% of the joist has been removed to make way for the hose.

 

Now I am not a structural engineer but I am a very experienced DIY-er and I would never have attempted this as surely it would compromise the joist? As can be seen on the photographs, the joist is 7" in depth and a depth of approximately 4" has been removed. In my opinion its a shocking job. I have taken some photos of the adjacent joist to show the dimensions.

 

My question is....is there any building control guidance/legislation on notching/drilling into joists and if so how would I obtain this? For me the job which has been undertaken cannot be compliant as the integrity of the joist is now surely compromised?

 

And my other questions would be, do I need to get somebody competent to come out and look at this and if so what needs to be done to make the joist good again?

 

Any advice would be greatly appreciated as I would like to challenge the contractor on the standard of works.

 

Many thanks

John

[MikeSharp01]

You are right to be concerned. Where is the hole in relation to the joist run, in the middle of the run or at one or other end? What sits on that joist, looks like a wall (hopefully a stud wall - which will be light and have a bottom stringer that can spread the load)? If its a brick wall then the load on the center of the joist is a triangle of the bricks and would need some calcs to work out what it is. Also does the joist sit on top of a wall below as this may make things a lot better. There are rules for notching a putting holes in joists. This is quite easy to follow: https://www.diydoctor.org.uk/projects/Notching_joist.htm

 

 

Edited July 10, 2019 by MikeSharp01

[Russell griffiths]

https://www.labc.co.uk/news/how-get-it-right-notches-holes-solid-timber-joists

[Russell griffiths]

That really is fairly shit on the shitometer. 

[JRR]

Thank you both for getting back to me, I really appreciate it and I am in total agreement that its sh*t!

 

I don't have the exact measurements to hand sorry, but the joist looks like it has been cut towards the end which is even more alarming. The room downstairs is the kitchen, and was an exact footprint of this particular bedroom, however that kitchen wall was removed some time ago with an RSJ installed. I need to take up a couple more boards to see what the end of the joist sits on and how far from the edge it has been cut so I will do that tomorrow. I am pretty sure the cut end sits on bricks but will confirm.

 

The joist is located just in front of the exterior wall, as shown in the additional photographs.....which I should have uploaded before sorry. The end of all of the floorboards sit on the joist in question but I do not believe there is any section of solid wall sitting on top of it. Regardless, I am still concerned.

 

I really do not understand why the contractor has done this when the hose could have been fed right to left between two joists and out the side of the house......which would have also made core drilling from inside much easier from a space perspective.

 

Thank you for the advice links, they are so useful.

 

I know that contractor will say that its only one joist and its absolutely fine but I don't buy it. Do you believe that I need to bring somebody competent out to look at this?

 

Many thanks

John

 

 

[joe90]

IMO the joist is next to the wall so won’t carry a great load, would have been worse for either of the other joists we can see in that pic but that does not make it right. A “get around” might be bolts through the joist either side of the new hole into the brickwork behind it, either rawlbolts or threaded bar into resin. Still a shit thing to do tho .

[Rob99]

That's a really poor job your builder has done. A classic case of "this'll be fine, it's only a small pipe".

 

You say there has been a steel beam installed below and the wall removed. If that's the case does that joist sit on that beam or, if not, does the beam now take all of the load of that side wall? It may be that the joist now takes virtually no load apart from the ends of the floor boards. If that's the case then you can at least be reassured that the builders incompetence hasn't created a structural issue.