Cutting a chunk out of joists to allow projector lift to fit?

Kiyoshi · 16 Jun 2015 at 10:17

Probably not but I wouldn't risk the structural integrity of my home for the sake of a projector.

JBuk · 16 Jun 2015 at 10:28

Kiyoshi said:
Probably not but I wouldn't risk the structural integrity of my home for the sake of a projector.

If its simply a joist as the op says then its not going to affect any of the buildings structure, if its the bottom chord of a roof truss then it would probably require looking at

Haggisman · 16 Jun 2015 at 11:18

JBuk said:
Only one joist needs altered , the house won't suddenly collapse into a pile of rubble

Surely that depends on what's above it, how old the house is, what the condition of the other surrounding joists are, etc.?

Kiyoshi · 16 Jun 2015 at 12:09

Without knowing anything about the construction, what floor he's talking about or what load it is expected to bear I still would not recommend cutting through ceiling joists. Somebody with real experience and who has actually seen the property should be consulted and not randomers on a computer forum saying yes or no blindly (myself included).

No offence intended. OP do what you think is best.

Jez · 16 Jun 2015 at 12:15

The obvious question here is whether a smaller lift is available which would fit within the 300mm centre, that lift looks massively over engineered for a little home cinema type projector.

the_r_sole · 16 Jun 2015 at 13:33

300mm centres could suggest a decent load

Cosimo · 16 Jun 2015 at 13:44

JBuk said:
Only one joist needs altered , the house won't suddenly collapse into a pile of rubble

Good to see you signing off the work.

Just need to make sure that OP has a safety helmet so that he can post the thread of the year after the dust has settled.

WillyNelson · 16 Jun 2015 at 22:10

Surely it's just like cutting in a loft hatch. Brace either side of where you're going to cut, cut the bit out, reinforce either side if the hole, done.

bitslice · 17 Jun 2015 at 03:15

WillyNelson said:
Surely it's just like cutting in a loft hatch. Brace either side of where you're going to cut, cut the bit out, reinforce either side if the hole, done.

Not really, a loft has no loading on it, a second floor could have a waterbed and a fat girl sitting on it.

You are asking two beams to take the loading of three, the only safe way of doing that is to double the stiffness of those two beams by adding two more to the existing beams and bolting them together.
When in doubt, overkill it.

I've seen them do this in America to fix a squeaky floor, they just doubled up on every beam. Massive overkill but timber is cheap over there.

wonko · 17 Jun 2015 at 05:58

IIUC any structural change, which would include load bearing joists, is notifiable to building control. Ref question 4.2g in http://www.planningportal.gov.uk/uploads/odpm/4000000011249.pdf. It's at least worth asking them whether it is notifiable and what calculations etc. they would expect to see.

Participant · 17 Jun 2015 at 07:13

Ignore

lude1962 · 18 Jun 2015 at 12:41

fornowagain said:

looks like this is just transferring the load to the two outer joists

how long are the joists?

do you ever intend to sell the house?

Savan_P · 18 Jun 2015 at 17:39

Forget building control. I would just do it sensibly, don't take out too much material and re-inforce the areas around the cut out.

DB_SamX · 19 Jun 2015 at 21:37

Savan_P said:
Forget building control. I would just do it sensibly, don't take out too much material and re-inforce the areas around the cut out.

What's "too much" and how do you quantify "re-inforce"? :confused:

To OP, if you aren't sure what you're doing, get professional help with the job. Know any structural engineers, or friends of friends, even a student, who could run the numbers to check?

No point me giving advice not knowing how your floor is put together. I know I wouldn't be cutting my floor joists without doing remedial work first.