[miamicuse]

I am remodeling this 35 year old house and throughout the house the walls
are made of a double layer of gypsum board as the layer underneath and a
layer of plaster / cement material on top. Total thickness is about 3/4".

http://i173.photobucket.com/albums/w...e/P1010626.jpg

This presents a problem in matching new wall with existing. If I use the
standard 3/8" or 1/2" wall board it will not match. I could use them in
areas where I torn down the entire wall from end to end, but in other areas
I have to match the existing thickness. I guess I have three options:

(1) Use one layer of 3/4" sheetrock and try to match it, or
(2) Use two layers of 3/8" sheetrock, or
(3) Furr out wall a bit to use one layer 3/8" wall board

Not sure which one is the most convenient and economical.

Also, electricians, plumbers, window installers have worked on the house and
there are numerous places I need to make a patch but the patching is
impossible since the cuts are done in an irregular fashion. See pic:

http://i173.photobucket.com/albums/w...e/P1010625.jpg

I try to cut them on a straight line and it's hopeless. Can't use a
recipricating saw because of the concrete layer underneath. Tried a angle
grinder and there were so much dust I could not stand it. Any advise?

Thanks,

Sum

[dadiOH]

MiamiCuse wrote:

Also, electricians, plumbers, window installers have worked on the
house and there are numerous places I need to make a patch but the
patching is impossible since the cuts are done in an irregular
fashion. See pic:

http://i173.photobucket.com/albums/w...e/P1010625.jpg

I try to cut them on a straight line and it's hopeless. Can't use a
recipricating saw because of the concrete layer underneath. Tried
a angle grinder and there were so much dust I could not stand it.
Any advise?

Plaster?


--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

[Mikepier]

On Feb 2, 11:09*pm, "MiamiCuse" wrote:
I am remodeling this 35 year old house and throughout the house the walls
are made of a double layer of gypsum board as the layer underneath and a
layer of plaster / cement material on top. *Total thickness is about 3/4".

http://i173.photobucket.com/albums/w...e/P1010626.jpg

This presents a problem in matching new wall with existing. *If I use the
standard 3/8" or 1/2" wall board it will not match. *I could use them in
areas where I torn down the entire wall from end to end, but in other areas
I have to match the existing thickness. *I guess I have three options:

(1) Use one layer of 3/4" sheetrock and try to match it, or
(2) Use two layers of 3/8" sheetrock, or
(3) Furr out wall a bit to use one layer 3/8" wall board

Not sure which one is the most convenient and economical.

There is no 3/4" sheetrock, only 5/8". I would think using 2 3/8"
sheetrock would be easiest.


Also, electricians, plumbers, window installers have worked on the house and
there are numerous places I need to make a patch but the patching is
impossible since the cuts are done in an irregular fashion. *See pic:

http://i173.photobucket.com/albums/w...e/P1010625.jpg

I try to cut them on a straight line and it's hopeless. *Can't use a
recipricating saw because of the concrete layer underneath. *Tried a angle
grinder and there were so much dust I could not stand it. *Any advise?

Use a circulating saw and adjust the thickness to 3/4". There will be
dust but it will get the job done quickly. Try wetting down the area a
bit or have a buddy hold a shop vac close to the cutting to minimize
dust.

[RicodJour]

On Feb 2, 11:09 pm, "MiamiCuse" wrote:
I am remodeling this 35 year old house and throughout the house the walls
are made of a double layer of gypsum board as the layer underneath and a
layer of plaster / cement material on top. Total thickness is about 3/4".

http://i173.photobucket.com/albums/w...e/P1010626.jpg

This presents a problem in matching new wall with existing. If I use the
standard 3/8" or 1/2" wall board it will not match. I could use them in
areas where I torn down the entire wall from end to end, but in other areas
I have to match the existing thickness. I guess I have three options:

(1) Use one layer of 3/4" sheetrock and try to match it, or
(2) Use two layers of 3/8" sheetrock, or
(3) Furr out wall a bit to use one layer 3/8" wall board

Not sure which one is the most convenient and economical.

Also, electricians, plumbers, window installers have worked on the house and
there are numerous places I need to make a patch but the patching is
impossible since the cuts are done in an irregular fashion. See pic:

http://i173.photobucket.com/albums/w...e/P1010625.jpg

I try to cut them on a straight line and it's hopeless. Can't use a
recipricating saw because of the concrete layer underneath. Tried a angle
grinder and there were so much dust I could not stand it. Any advise?

Yep. Don't let your tradesmen cut nasty holes for you to patch. You
should cut the openings or have the tradesmen cut straight lines.

A reciprocating saw will work just fine, you'll just go through a lot
of blades. Most reciprocating saws accept the blade in a reversed
position (teeth are facing up instead of down when the saw is held
horizontally). Reversing the blade allows you to have a much lower
angle of attack which is necessary since you don't have blade
clearance behind the drywall. Tape the vacuum hose to the end of the
saw so it will pick up most of the finer dust as you cut.

As an alternative, it's easier to cut complicated outlines in the new
drywall than trying to cut into the existing wall. You'll have to
clean up the edges of the cutouts, but you can use scribe cutting
techniques to cut any sort of outline to follow the contours of the
cutout. You mark the scribe line on the new drywall patch with a
compass and cut to the line with a drywall keyhole saw. It goes
fairly quickly and will cut way down on the amount of dust you'd be
blowing around cutting the drywall with a power tool.

I attach scrap plywood blocking behind the drywall so it's fastened on
both sides of the cutout every foot or so (the blocking ends up
looking like a ladder running up inside a long cutout). Then you can
attach your drywall, or cardboard/plywood shims, to the blocking. I
prefer to have the cutout repair drywall sit just a bit lower than the
original wall surface as it makes taping easier. You'll end up
bridging over the entire cutout and it's better to have one smooth,
gradual bump, than to have bumps on either side of the cutout from the
tape.

I would not use a single layer of 3/8" drywall. 5/8" should work
nicely. If the existing wall surface is flat and true, you could shim
that out a bit with some cardboard to you won't need as much joint
compound. Standard fiberglass mesh tape would be a poor choice for
your repair. It's noticeably thicker than paper joint tape and the
loose ends end up requiring more compound to cover them (and you can't
sand them), so the bump ends up being bigger. Either use paper tape,
or something like Tuffglass tape (TKO Coatings) - that's a flat woven
tape that is much thinner than standard fiberglass tape.

R

[Joe]

snip

I try to cut them on a straight line and it's hopeless. Can't use a
recipricating saw because of the concrete layer underneath. Tried a angle
grinder and there were so much dust I could not stand it. Any advise?

Buy the cheapest saber saw (or jig saw) that Harbor Freight has. Break
off or grind off a blade to the exact length that will cut the
thickness you want and have at it. Pros use this same trick for
removing just the layers of old underlayment, flooring and what have
you without tearing up the subfloor. HTH

Joe

[miamicuse]

"Mikepier" wrote in message
...
On Feb 2, 11:09 pm, "MiamiCuse" wrote:
I am remodeling this 35 year old house and throughout the house the walls
are made of a double layer of gypsum board as the layer underneath and a
layer of plaster / cement material on top. Total thickness is about 3/4".

http://i173.photobucket.com/albums/w...e/P1010626.jpg

This presents a problem in matching new wall with existing. If I use the
standard 3/8" or 1/2" wall board it will not match. I could use them in
areas where I torn down the entire wall from end to end, but in other
areas
I have to match the existing thickness. I guess I have three options:

(1) Use one layer of 3/4" sheetrock and try to match it, or
(2) Use two layers of 3/8" sheetrock, or
(3) Furr out wall a bit to use one layer 3/8" wall board

Not sure which one is the most convenient and economical.

There is no 3/4" sheetrock, only 5/8". I would think using 2 3/8"
sheetrock would be easiest.

I might either use 2 3/8" or may be fur out the wall a bit more with 3/8"
furring strips. May be furring strips will work out better.


Also, electricians, plumbers, window installers have worked on the house
and
there are numerous places I need to make a patch but the patching is
impossible since the cuts are done in an irregular fashion. See pic:

http://i173.photobucket.com/albums/w...e/P1010625.jpg

I try to cut them on a straight line and it's hopeless. Can't use a
recipricating saw because of the concrete layer underneath. Tried a angle
grinder and there were so much dust I could not stand it. Any advise?

Use a circulating saw and adjust the thickness to 3/4". There will be
dust but it will get the job done quickly. Try wetting down the area a
bit or have a buddy hold a shop vac close to the cutting to minimize
dust.

Thanks, It's hard using circular saw moving up and down with that weight. I
wish there is a laser beam cutting tool.

[miamicuse]

"RicodJour" wrote in message
...
On Feb 2, 11:09 pm, "MiamiCuse" wrote:
I am remodeling this 35 year old house and throughout the house the walls
are made of a double layer of gypsum board as the layer underneath and a
layer of plaster / cement material on top. Total thickness is about
3/4".

http://i173.photobucket.com/albums/w...e/P1010626.jpg

This presents a problem in matching new wall with existing. If I use the
standard 3/8" or 1/2" wall board it will not match. I could use them in
areas where I torn down the entire wall from end to end, but in other
areas
I have to match the existing thickness. I guess I have three options:

(1) Use one layer of 3/4" sheetrock and try to match it, or
(2) Use two layers of 3/8" sheetrock, or
(3) Furr out wall a bit to use one layer 3/8" wall board

Not sure which one is the most convenient and economical.

Also, electricians, plumbers, window installers have worked on the house
and
there are numerous places I need to make a patch but the patching is
impossible since the cuts are done in an irregular fashion. See pic:

http://i173.photobucket.com/albums/w...e/P1010625.jpg

I try to cut them on a straight line and it's hopeless. Can't use a
recipricating saw because of the concrete layer underneath. Tried a
angle
grinder and there were so much dust I could not stand it. Any advise?

Yep. Don't let your tradesmen cut nasty holes for you to patch. You
should cut the openings or have the tradesmen cut straight lines.

I tried to tell them to cut straight lines but they never listen to me.
They told me this is not regular sheetrock so they had to pound it out.


A reciprocating saw will work just fine, you'll just go through a lot
of blades. Most reciprocating saws accept the blade in a reversed
position (teeth are facing up instead of down when the saw is held
horizontally). Reversing the blade allows you to have a much lower
angle of attack which is necessary since you don't have blade
clearance behind the drywall. Tape the vacuum hose to the end of the
saw so it will pick up most of the finer dust as you cut.

I am getting a lot of kicks when the saw blade hits the concrete wall right
behind it. It's not working this way I have to think about a different
approach.


As an alternative, it's easier to cut complicated outlines in the new
drywall than trying to cut into the existing wall. You'll have to
clean up the edges of the cutouts, but you can use scribe cutting
techniques to cut any sort of outline to follow the contours of the
cutout. You mark the scribe line on the new drywall patch with a
compass and cut to the line with a drywall keyhole saw. It goes
fairly quickly and will cut way down on the amount of dust you'd be
blowing around cutting the drywall with a power tool.

I attach scrap plywood blocking behind the drywall so it's fastened on
both sides of the cutout every foot or so (the blocking ends up
looking like a ladder running up inside a long cutout). Then you can
attach your drywall, or cardboard/plywood shims, to the blocking. I
prefer to have the cutout repair drywall sit just a bit lower than the
original wall surface as it makes taping easier. You'll end up
bridging over the entire cutout and it's better to have one smooth,
gradual bump, than to have bumps on either side of the cutout from the
tape.

I would not use a single layer of 3/8" drywall. 5/8" should work
nicely. If the existing wall surface is flat and true, you could shim
that out a bit with some cardboard to you won't need as much joint
compound. Standard fiberglass mesh tape would be a poor choice for
your repair. It's noticeably thicker than paper joint tape and the
loose ends end up requiring more compound to cover them (and you can't
sand them), so the bump ends up being bigger. Either use paper tape,
or something like Tuffglass tape (TKO Coatings) - that's a flat woven
tape that is much thinner than standard fiberglass tape.

R


RicodJour thanks I think I may try to fur out the wall to flush with
existing surface instead of using thicker or double sheets. This will make
future repair easier, I think...it's good to know about Tuffglass tape I
will need it where I am matching new to old walls.

[spammer]

I use a utility knife to score the cement board and then snap it.
Works great and no flying dust.

[miamicuse]

"Joe" wrote in message
...
snip

I try to cut them on a straight line and it's hopeless. Can't use a
recipricating saw because of the concrete layer underneath. Tried a
angle
grinder and there were so much dust I could not stand it. Any advise?

Buy the cheapest saber saw (or jig saw) that Harbor Freight has. Break
off or grind off a blade to the exact length that will cut the
thickness you want and have at it. Pros use this same trick for
removing just the layers of old underlayment, flooring and what have
you without tearing up the subfloor. HTH

Joe

Thank you, I might try that. It will be tricky to break off a blade. I
wonder if I can somehow set a depth, is there any attachment to a jigsaw
that will allow you to reduce the depth?

[miamicuse]

"spammer" wrote in message
...
I use a utility knife to score the cement board and then snap it.
Works great and no flying dust.

It is not cement board it is 3/*" thick plaster on top of sheet rock, around
corners and edges it has this metal wire mesh too.

It is hard to snap when it's already mounted on the wall with screws every 8
inches or so.

[SteveB[_2_]]

FWIW, I had to cut some stucco, which is similar to cement board. A SawZall
made terrible jagged cuts, and pulled on the stucco making fractures that
looked like a giant cobweb. I got a SkilSaw with a metal cutting blade, set
the depth properly, and breezed right through it. I did have a helper with
a vacuum to help keep the dust down, but there was still a lot.

Steve

[Pisano]

On Wed, 6 Feb 2008 18:44:28 -0800, "SteveB"
wrote:

FWIW, I had to cut some stucco, which is similar to cement board. A SawZall
made terrible jagged cuts, and pulled on the stucco making fractures that
looked like a giant cobweb. I got a SkilSaw with a metal cutting blade, set
the depth properly, and breezed right through it. I did have a helper with
a vacuum to help keep the dust down, but there was still a lot.

Steve



If what you are using is similar to "Durock", you don't really
need to use a saw.

You can score and break it like drywall.

[RicodJour]

On Feb 6, 7:59 pm, "MiamiCuse" wrote:

I am getting a lot of kicks when the saw blade hits the concrete wall right
behind it. It's not working this way I have to think about a different
approach.

If you're hitting the concrete block the angle isn't low enough. If
there's furring attached to the concrete block, you will be able to
use a longer blade installed backwards in a sawzall. That will give
you the clearance you need.

If there isn't any furring between the concrete block and the wall
covering you could just infill the whole thing with plaster. Clean up
the loose edges and loose paper on the drywall and start plastering.

R

[Jeff[_3_]]

This looks like it would be perfect for your requirement.
http://www.canadiantire.ca/browse/pr... 1202409631042

However a brief, very brief, net search didn't find a U.S. counterpart. The
customer reviews also indicate it isn't very powerful so might not cut
through your walls anyway. You may have better luck finding an alternate
brand with more power locally.



"MiamiCuse" wrote in message
...

"Mikepier" wrote in message
...
On Feb 2, 11:09 pm, "MiamiCuse" wrote:
I am remodeling this 35 year old house and throughout the house the walls
are made of a double layer of gypsum board as the layer underneath and a
layer of plaster / cement material on top. Total thickness is about 3/4".

http://i173.photobucket.com/albums/w...e/P1010626.jpg

This presents a problem in matching new wall with existing. If I use the
standard 3/8" or 1/2" wall board it will not match. I could use them in
areas where I torn down the entire wall from end to end, but in other
areas
I have to match the existing thickness. I guess I have three options:

(1) Use one layer of 3/4" sheetrock and try to match it, or
(2) Use two layers of 3/8" sheetrock, or
(3) Furr out wall a bit to use one layer 3/8" wall board

Not sure which one is the most convenient and economical.

There is no 3/4" sheetrock, only 5/8". I would think using 2 3/8"
sheetrock would be easiest.

I might either use 2 3/8" or may be fur out the wall a bit more with 3/8"
furring strips. May be furring strips will work out better.


Also, electricians, plumbers, window installers have worked on the house
and
there are numerous places I need to make a patch but the patching is
impossible since the cuts are done in an irregular fashion. See pic:

http://i173.photobucket.com/albums/w...e/P1010625.jpg

I try to cut them on a straight line and it's hopeless. Can't use a
recipricating saw because of the concrete layer underneath. Tried a angle
grinder and there were so much dust I could not stand it. Any advise?

Use a circulating saw and adjust the thickness to 3/4". There will be
dust but it will get the job done quickly. Try wetting down the area a
bit or have a buddy hold a shop vac close to the cutting to minimize
dust.

Thanks, It's hard using circular saw moving up and down with that weight.
I wish there is a laser beam cutting tool.

[a]

Jeff wrote:
This looks like it would be perfect for your requirement.
http://www.canadiantire.ca/browse/pr... 1202409631042

However a brief, very brief, net search didn't find a U.S. counterpart. The
customer reviews also indicate it isn't very powerful so might not cut
through your walls anyway. You may have better luck finding an alternate
brand with more power locally.



"MiamiCuse" wrote in message
...
"Mikepier" wrote in message
...
On Feb 2, 11:09 pm, "MiamiCuse" wrote:
I am remodeling this 35 year old house and throughout the house the walls
are made of a double layer of gypsum board as the layer underneath and a
layer of plaster / cement material on top. Total thickness is about 3/4".

http://i173.photobucket.com/albums/w...e/P1010626.jpg

This presents a problem in matching new wall with existing. If I use the
standard 3/8" or 1/2" wall board it will not match. I could use them in
areas where I torn down the entire wall from end to end, but in other
areas
I have to match the existing thickness. I guess I have three options:

(1) Use one layer of 3/4" sheetrock and try to match it, or
(2) Use two layers of 3/8" sheetrock, or
(3) Furr out wall a bit to use one layer 3/8" wall board

Not sure which one is the most convenient and economical.
There is no 3/4" sheetrock, only 5/8". I would think using 2 3/8"
sheetrock would be easiest.
I might either use 2 3/8" or may be fur out the wall a bit more with 3/8"
furring strips. May be furring strips will work out better.

Also, electricians, plumbers, window installers have worked on the house
and
there are numerous places I need to make a patch but the patching is
impossible since the cuts are done in an irregular fashion. See pic:

http://i173.photobucket.com/albums/w...e/P1010625.jpg

I try to cut them on a straight line and it's hopeless. Can't use a
recipricating saw because of the concrete layer underneath. Tried a angle
grinder and there were so much dust I could not stand it. Any advise?
Use a circulating saw and adjust the thickness to 3/4". There will be
dust but it will get the job done quickly. Try wetting down the area a
bit or have a buddy hold a shop vac close to the cutting to minimize
dust.
Thanks, It's hard using circular saw moving up and down with that weight.
I wish there is a laser beam cutting tool.





Ooooh, that's nice - I'll pop over to Can Tire and buy one for the op and
ship it to them for my cost only...

a