Stihl sawing a new doorway.

[bulltaco]

I'm getting ready to fire up a stihl saw to cut out a new doorway in a brick wall. (I've got the water kit on it!)
I've marked the verticals on the wall and propped the joists. The only slight problem is I only have a 12" blade which is about ½" short to go all the way through but that should be OK.
It has to be a 838mm door for the new disabled access rules, can anyone just confirm the the size of opening I need to cut out is 925mm?. And how exact does it need to be?.

 

[JamesBeasley]

Hello

I am guessing that the thickness of the frame is 44mm? If it is then the s/o you need is - 955mm across.

If it is not 44mm then follow this simple check below: -

Size of door + Frame + 10mm either side to fit the door in and level it + 7mm to allow door to swing in the opening (hinges and leading edge clearance). Then add your totals up and that is what you cut.

In your case I added 838mm (door), 88mm (thickness of frame), 20mm (gap either side of 10mm), 7mm (for swinging door) = 953mm (added a couple of mm as it never hurts)

Hope this helps....

 

[bulltaco]

Thanks for that, used your formula, sawed the vertical lines from each side (they lined up perfectly!) and it's looking good.

 

[ColJack]

don't they use special chainsaws to do door openings these days?

 

[xerxes]

The Arbortech Allsaw. I wish I could afford one.

 

[ColJack]

that's no good for putting windows and doors in, it only cuts to 120mm... what use is that?

 

[mattylad]

I watched Alan Herd cutting a doorway with a chainsaw on one of Tommy's TV shows, it went though nice & easily, a tad more depth than 120mm

 

[JamesBeasley]

I am glad to have been of assistance

In relation to the chain saw for cutting out door openings.... never used in 'real life' lol. I am a site manager in construction and the only tool we would ever use is a masonry saw (aka stihl saw / spinner / petrol saw etc).

Don't forget your local hire shop for these expensive items. The manager in me has to tell you that you must wear the correct PPE for the task in hand (Personal Protective Equipment) Like goggles, gloves and ear defenders!!! If you hire a diamond blade for the mansonry saw the hire shop will charge you for every mm you use... so if you have several cuts it may well be cheaper to buy your own, they cost around £40-£200 so shop around.