breaking through, worth the effort to use dust screens

[needmorstuff]

yes negative air pressure... I'll look into it.

 

[cjard]

Nip off to the scrappie and get a couple of car radiator fans, mount them in a board suitably sized for a window/door opening.. Can either use positive or negative pressure depending on where is best to mount it/which side of the wall has the best airtightness

Makita saws have had tap connections for at least 10 years.. Are they Stihl not fitted to other brands? Dear oh dear..

 

[needmorstuff]

Nip off to the scrappie and get a couple of car radiator fans, mount them in a board suitably sized for a window/door opening.. Can either use positive or negative pressure depending on where is best to mount it/which side of the wall has the best airtightness

Makita saws have had tap connections for at least 10 years.. Are they Stihl not fitted to other brands? Dear oh dear..

oh thats so bad its good!

 

[bernardgreen]

Can either use positive or negative pressure

Positive pressure in the room will force dust under the doors, out of the room and into the rest of the house.

 

[endecotp]

Positive pressure in the room will force dust under the doors, out of the room and into the rest of the house.

And positive pressure in the rest of the house will...... ?

 

[cjard]

Positive pressure in the room will force dust under the doors, out of the room and into the rest of the house.

You're quoting me out of context there.

When I said "depending on where is best to mount it/which side of the wall [that youre going to saw through] has the best airtightness" (the rest of the sentence you snipped) I meant:

If there's some gaping hole in the extension, e.g. the eaves of the roof are unfinished/there's no plasterboard/etc, then it doesn't make much sense to put your extract fan in the extension and use negative pressure to suck the dust away from entering the rest of the house, so you'd mount it in a window of the house, then apply positive pressure to the house to blow the dust into the extension..

Conversely, if the house is a draughty old victorian semi and the extension is brand new, well built and sealed really well then you're best off mounting the fan in the extension and running negative pressure...

Ergo, pick whichever side of the to-be-cut wall is the most airtight, and apply the relevant positive/negative pressure to that side for best results. If airtightness of both sides is crap, there are probably bigger problems than a bit of dust

Wet cut should be employed regardless

 

[needmorstuff]

You're quoting me out of context there.

When I said "depending on where is best to mount it/which side of the wall [that youre going to saw through] has the best airtightness" (the rest of the sentence you snipped) I meant:

If there's some gaping hole in the extension, e.g. the eaves of the roof are unfinished/there's no plasterboard/etc, then it doesn't make much sense to put your extract fan in the extension and use negative pressure to suck the dust away from entering the rest of the house, so you'd mount it in a window of the house, then apply positive pressure to the house to blow the dust into the extension..

Conversely, if the house is a draughty old victorian semi and the extension is brand new, well built and sealed really well then you're best off mounting the fan in the extension and running negative pressure...

Ergo, pick whichever side of the to-be-cut wall is the most airtight, and apply the relevant positive/negative pressure to that side for best results

nice sensible reply.

 

[^woody^]

Monster thread for what should be a dust sheet and a poly sheet propped up against the ceiling and walls, leaving just enough room to work in.

KISS