Choosing a circular saw for cutting through floorboards

[cdbe]

You'll almost certainly not get the t&g up intact unless you remove or punch through all the nails. No-one will want them unless for firewood.

Just put a bit of tape on your multitool blade to act as a depth marker.

 

[Koolpc]

I don't think a multi tool is particularly good for cutting floorboards in situ. It's safer in the sense that it won't kickback, but more dangerous insofar as there's no depth stop so it might cut through an electric cable or pipe under the boards.

It would also be more tiring to use if I'm cutting a lot of boards, as a circular saw rests on the floor and glides along, whereas with the multi tool you have to carry the weight of it and try not to let it go too deep.

You only need to cut one tongue....the rest could be pried up easily and carefully...

 

[Murdochcat]

I'd but mains one.
Watch out for pipes. Seen a few hit with saw

and watch out for electric cables too …. For a long time sparks and plumbers cut notches out of the top of joists …..

 

[opps]

My Festool oscillating saw has a depth stop. When using my Fein, I just put a spacer under the body to reduce the depth of cut.

 

[morqthana]

Wouldn't it reduce the damage to the boards though if I cut the T&G before prying them up?

I want to minimise the damage as I think someone will be more likely to want to collect them for free if they're intact. I can chop them up to fit in the car and take them down the tip though if no-one wants them.

Once you've cut through the tongues you no longer have T&G floorboards, just narrow lengths of old softwood, of little interest I suspect.

 

[morqthana]

You'll almost certainly not get the t&g up intact unless you remove or punch through all the nails.

Cut floor brads can be a right ****** to punch through, particularly if the house dates from an age when the timber used for the joists had more than 8 growth rings per inch.

What you can do if you want to re-use, having sawn the first tongue away, is use a hole saw to cut round the nails. The neat round holes in the boards can be plugged with glued-in dowels, the old nails pulled out, and the boards screwed down when replaced.

The OP doesn't want to re-use, I know, which I think he may regret - chipboard panels are horrible things.

 

[Derek M]

You'll almost certainly not get the t&g up intact unless you remove or punch through all the nails. No-one will want them unless for firewood.

Just put a bit of tape on your multitool blade to act as a depth marker.

Fair enough. If no-one will want to re-use them maybe I won't worry about damaging them, although I could potentially use them myself in the future to clad a garden house in my parent's garden, as I saw someone who did that on a programme the other day.

 

[Derek M]

and watch out for electric cables too …. For a long time sparks and plumbers cut notches out of the top of joists …..

Yeah, as I'm going to be getting the electrics rewired I'll get any cables moved lower down if necessary, to avoid any issues in future.

 

[Derek M]

My Festool oscillating saw has a depth stop. When using my Fein, I just put a spacer under the body to reduce the depth of cut.

My Einhell multitool doesn't have a depth stop unfortunately, but I'll try to fashion a spacer.

 

[Derek M]

Once you've cut through the tongues you no longer have T&G floorboards, just narrow lengths of old softwood, of little interest I suspect.

Maybe useful for cladding a garden house?

 

[Derek M]

Cut floor brads can be a right ****** to punch through, particularly if the house dates from an age when the timber used for the joists had more than 8 growth rings per inch.

What you can do if you want to re-use, having sawn the first tongue away, is use a hole saw to cut round the nails. The neat round holes in the boards can be plugged with glued-in dowels, the old nails pulled out, and the boards screwed down when replaced.

The OP doesn't want to re-use, I know, which I think he may regret - chipboard panels are horrible things.

What's the problem with chipboard panels (I did originally say plywood but I'm not sure it will be worth the extra costs over chipboard/OSB when it won't be visible)?

If they're problematic in houses where there's cold, damp air under the floorboards, that won't be an issue in my first-floor flat as there's just a solid concrete slab under the joists.

 

[StephenStephen]

I've gone back to the beginning of the thread.
We recently sound insulated an upstairs flat, and moved cables and pipes under the floor.

We took up very very few floorboards to do so.

If you don't think it's worth the extra cost to use ply, why do you think it's worth the extra cost (and time and hassle) to replace the entire floor with new materials which are poorer quality than you currently have?

 

[Derek M]

I've gone back to the beginning of the thread.
We recently sound insulated an upstairs flat, and moved cables and pipes under the floor.

We took up very very few floorboards to do so.

If you don't think it's worth the extra cost to use ply, why do you think it's worth the extra cost (and time and hassle) to replace the entire floor with new materials which are poorer quality than you currently have?

I didn't say I don't think its worth the extra cost to use ply, I just said I'm not sure.

When I soundproof the bedroom and living room I'll need to fit clip+channel+two layers of plasterboard on the ceiling and all the walls, and with the floor I'm going to remove the joists, use levelling compound and then fit rubber pads on that, with two overlapping layers of ply/OSB on top which will bring the floor back to the current level.

If I left the floor as it is, it would make the rest of the soundproofing useless as the noise would just travel from the other flats through the structure and up into my flat through the floor, and if I don't do a thorough job with the floor and then find that it's leaking noise after I've treated the rest of the room, it will be a nightmare trying to re-do it, so I need to do it properly the first time. It may be that ply is the only suitable material for this job, but I wanted to know why morqthana thinks chipboard panels are "horrible things".

I'm not going to soundproof the hall, but it will be a good opportunity to practice lifting the floorboards and laying panels, which will also make it easier to lift the floor when the electrician comes to wire up the new circuit, and I need to replace the skirting board and door frames too.

 

[Koolpc]

I'm going to remove the joists,

'Remove the joists?'

 

[Mike13]

If they're problematic in houses where there's cold, damp air under the floorboards, that won't be an issue in my first-floor flat as there's just a solid concrete slab under the joists.

'Remove the joists?'

As above, it is not "joists" really, it is just spacers to bring the flooring to a defined level.