100mm hole through wood....deep

[Delvis]

The need has arisedto cut a 100mm hole through some wood at our house, trouble is it's probably double that in depth!

A time have any pointers? We do have adiamoned core drill bit but it's somewhat useless on wood

 

[Delvis]

How accessible is it? Can it be approached from both sides?

If it's something that can be moved and worked on at a bench or similar?

Not really got an idea but those questions might help the next person along

No, it's for an extraction fan - but it can be approached from both sides technically

So there's render one side (which the core drill will be great for) then pretty much just wood the other for some bizarre reason

 

[Delvis]

Holesaw with extension rod, you will have to chisel the middle out a few times

That's what I didnt want to do really Purchased too much already!

 

[Delvis]

Yeah, we have a 102mm holesaw,. It the 100mm pipe doesn't fit through it ironically as 100mm is the internal size of the pipe!

Lesson learned I guess.

 

[Delvis]

Are you sure it's all wood?

Have you put a single hole through the entire depth to confirm?

Yep.

It's a couple of pieces at least

 

[Delvis]

Isn't a piece of wood of that size likely to be structural? Sticking a 4" hole through it might not be a good idea.

From what I've been told it shouldn't be because of where it is, as the space where it's going is probably double that, if not more

 

[Delvis]

If it's not one single piece of paper timber then using a hole saw shouldn't be too difficult?

We wanted to go through in one go rather than cut a bit, chip it out, cut a bit, chip it out etc.

We've already pruchased loads of bits and bobs and in the run-up to Christmas it's adding up, so I came here for for answers

We may need to just coughup and buy the larger hole saw

If it's 200mm or more thick I would imagine the first question would be "is it it OK to drill a hole that big through it?" For a timbers of that size it may well be weight bearing. Where is this 200mm thick piece of timber?

For joists, I thought the rule of thumb was not to notch more than a 1/8 of the width, or 1/2 if you drill on the centre of the width. (id check that)

It's more than one piece of timber.

It's above the external door from the kitchen on the side of the house. Essentially the kitchen needs an extractor fan put in to comply with building regulations.

Normally, we'd of expected a frame around the door, a gap of 20-30cm then the frame to the top floor, but this just appears to have multiple pieces of wood stuck in this gap.

 

[Delvis]

Are you just refitting a kitchen or is this part of a build that will be inspected by a building regs officer?

The latter.

It's because of the building inspector it needs an extraction unit.

 

[Delvis]

Find a better place for it just through masonry and use ducting to the extractor. Personally I wouldn't want to be exiting a building above a doorway anyway due to lintel and load stresses there anyway.

No other option as the kitchen is in the 'middle' of the house (at the side)

Ducting is going to be used from the cooker hood to the wall,ducting through the wall.

 

[Delvis]

Sounds like it's a old wooden lintel that's been fabricated from scraps. It's not unheard of. I'd be looking at going through a wall.

The extension was built within the last ten years I believe.

And as per the last post,no other walls to go through due to the position of the kitchen

 

[Delvis]

Straight up and through the roof?

Ground floor

 

[Delvis]

If it's above a door opening, it could just be a filler piece or it could be a lintel. I'd suggest getting someone in to advise before just drilling through it

My assumption is it's part lintel part filler

The way it's intending on being cut is so it affectshalf and half of another piece of timber essentially

I'll see if we can contact the original contractors

 

[Delvis]

Possible stupid question incoming. Can you not use smaller ducting?
A 50mm hole can move as much air as a 100mm hole if the fan is running faster.

I guess we could yes, just standard extraction ducting is usually 100mm circle, or rectangle.

Yes still applies, straight up, through the room above as well, and even then out of the wall at floor level above to avoid going through wood?

I guess, be a painting run through upstairs though as there's a bedroom and bathroom above. I contemplated about going I to the ceiling then across out the wall but I think there's a lot of pipe work under the floor boards above.

Or two 70mm holes, or three 57mm holes and a splitter of some sort. These being the same XSA as 1 100mm hole.

ALL the holes

 

[Delvis]

Joists and lintels have completely different loadings, you should not randomly drill holes in lintels

Can you put up some pics?

Not.home for a few days now.

Think galley kitchen, door down the end with a window next to it. Above window and door is about 30cm of space,all of this is wood, but not one solid piece

 

[Delvis]

It could be cladding a steel lintel above the window and door like this

http://chippers.me.uk/gallery/house/extension/Photo-2018-07-01-13-32-39_0391.JPG

Should have said, the extension is a wood frame from what I remember

 

[Delvis]

It's very likely the lintel then, like so

http://anewhouse.com.au/2013/08/openings-in-timber-frame/

I would agree but a lintel would usually be the depth of the house wall wouldn't it?

 

[Delvis]

Not always with timber construction as the base plate timber of the above panel may be wider than the lintel

Is it brick/block clad and timber inside?

Rendered on the outside

 

[Delvis]

What's at the bottom of the render? Are there a few courses of bricks above the ground before the render starts? I've used double 200mm x 75mm timbers bolted together as lintels on timber framing and you really don't want to drill through those. They could be picking up the load from the teh roof, you really need to be at least 200mm from the window/door reveal to the edge of the hole before you start drilling (professional wood butcher)

Yeah there's a few bricks at the bottom before the render

Can you explain the part where you say '200mm from the window/door reveal'?

Edit: think I get it now. I can measure when I'm home again, but going by what you say it might be 200mm from the top of the window reveal

 

[Delvis]

A few weeks ago at work I had to make a few holes for a 100mm plastic air vent pipe and i used a 105mm hole saw

Yep, sounds like it would work as the pipe is usually about 104mm in total

I'll know for another time at least

 

[Delvis]

The lintel above your window/door frame, whether it's metal or timber will be supported either side of the opening, usually by 150mm on both sides, so if your opening is 1m wide then the lintel length would be 1.3m long. 150mm bearing either side (left and right) , whether it sits on timber or brickwork. That's what I getting at, you'd need to miss that if you didn’t have room above it to fit duct. Probably best off doing an exploritory hole to see what's there above lintel, or drill it one side of lintel, phew! Pictures would help

Sort of getting it

I'll try get pictures when I'm back home. But literally imagine a galley kitchen, at the end you have the single door, a single window, then a bit of space next to the window where the poop pipe runs from upstairs, that's how wide everything is

So I guess in short I can't go either side of the lintel, as the space doesnt exist, I can only go above it