Notched Joist Problem
 

My contractor notched my joists in the kitchen about an inch from the
top. The floor joists are 9" in height and 1 1/2" inch in width and 15'
in length. It is under the kitchen. The notch cut is about 1" cubed in
volume and at the top. Also the notches are 5' 8" from the start of the
span. Every joist was notched the same way to fit a gas pipe (black pipe).

How bad is this? Is it something to lose sleep over?

THanks

BN wrote:
My contractor notched my joists in the kitchen about an inch from the
top. The floor joists are 9" in height and 1 1/2" inch in width and 15'
in length. It is under the kitchen. The notch cut is about 1" cubed in
volume and at the top. Also the notches are 5' 8" from the start of the
span. Every joist was notched the same way to fit a gas pipe (black pipe).

How bad is this? Is it something to lose sleep over?

Not sure where you're located and what your local code is, but the NY
State IRC (International Residential Code with minor modifications)
prohibits notching in the middle third of the span. That 8" puts the
notch in the middle third.

The depth of the notch, if it wasn't in the middle third, is of an
acceptable depth - depth of notch/6 = 1.5"

It's not a great situation. You may never have a problem, but your
contractor damaged your house and it doesn't conform to the IRC. Ask
him what he's going to do to strengthen the weakened joists. Sistering
a 3-4' 2x6 or 2x8 under the notch would stiffen the localized weakness.
The added pieces should be glued and nailed.

Generally, whenever an electrical or plumbing line is run perpendicular
to the joists it should be drilled instead of notched. It doesn't
weaken the joist as much and keeps the line away from the face of the
joist, thereby preventing someone inadvertantly hitting it with a nail.

R

BN wrote:
My contractor notched my joists in the kitchen about an inch from the
top. The floor joists are 9" in height and 1 1/2" inch in width and 15'
in length. It is under the kitchen. The notch cut is about 1" cubed in
volume and at the top. Also the notches are 5' 8" from the start of the
span. Every joist was notched the same way to fit a gas pipe (black pipe).

How bad is this? Is it something to lose sleep over?

THanks


The notch has reduced the effective depth of the
joist by the depth of the notch. So assume the
notch is 1 inch deep the effective depth of the
joist is 9" - 1" = 8"

If that is a 15 foot clear span (no support except
at the ends) it is either unacceptable or close to
unacceptable depending on the joist spacing.
Based on my tables you should have 2 x 10's and
they should be Douglas fir or larch on 16" centers
as a minimum. The plumber should have put the
pipe through holes near the center of the joist.
That would not reduce the strength of the joist
whereas a notch on the top or the bottom does
reduce the strength

RicodJour wrote:
BN wrote:

My contractor notched my joists in the kitchen about an inch from the
top. The floor joists are 9" in height and 1 1/2" inch in width and 15'
in length. It is under the kitchen. The notch cut is about 1" cubed in
volume and at the top. Also the notches are 5' 8" from the start of the
span. Every joist was notched the same way to fit a gas pipe (black pipe).

How bad is this? Is it something to lose sleep over?


Not sure where you're located and what your local code is, but the NY
State IRC (International Residential Code with minor modifications)
prohibits notching in the middle third of the span. That 8" puts the
notch in the middle third.

The depth of the notch, if it wasn't in the middle third, is of an
acceptable depth - depth of notch/6 = 1.5"

It's not a great situation. You may never have a problem, but your
contractor damaged your house and it doesn't conform to the IRC. Ask
him what he's going to do to strengthen the weakened joists. Sistering
a 3-4' 2x6 or 2x8 under the notch would stiffen the localized weakness.
The added pieces should be glued and nailed.

Generally, whenever an electrical or plumbing line is run perpendicular
to the joists it should be drilled instead of notched. It doesn't
weaken the joist as much and keeps the line away from the face of the
joist, thereby preventing someone inadvertantly hitting it with a nail.

R


How would you install the gas pipe the OP had installed? I guess you'd
have to hang it below the joists.... I'm serious. I need to have a gas
line moved in the near future.

Brad

WWPA has a pdf describing limits of notching.
I'll e-mail a copy on request.

Alternatively, give the group the same kind of info that BN provided
and you will probably get an answer.
TB

This isn't a troll, and I don't have anything to offer regarding the OP
notch question.
But supposing the plumber _did_ drill holes near the centerline of the
joists. How do you then go about getting the piece of rigid black gas
pipe in those holes? Do you cut an access through the exterior of the
house? Do you use lots of short lengths coupled together? Just
curious...

-Kevin

George E. Cawthon wrote:

The notch has reduced the effective depth of the joist by the depth of
the notch. So assume the notch is 1 inch deep the effective depth of
the joist is 9" - 1" = 8"

If that is a 15 foot clear span (no support except at the ends) it is
either unacceptable or close to unacceptable depending on the joist
spacing. Based on my tables you should have 2 x 10's and they should be
Douglas fir or larch on 16" centers as a minimum. The plumber should
have put the pipe through holes near the center of the joist. That
would not reduce the strength of the joist whereas a notch on the top
or the bottom does reduce the strength



The kitchen is 15' x 10'. The joist span is 15'. There are 6 joists
that are 14" apart. The 1st and last joists are 6" from the
joist-parallel wall. Although there is a double joist 2 feet from the
wall and one more 5 inches from the double joist. So its a total of 6
joists spaced 14" apart but starting 6" from either wall plus the 3
joists I mentioned for a total of 9!

Luckily the double joist is under the cabinet and range side of the
kitchen. We may put granite or quartz countertop.


Does that change anything?

On 2005-10-06, kevin wrote:

But supposing the plumber _did_ drill holes near the centerline of the
joists. How do you then go about getting the piece of rigid black gas
pipe in those holes? Do you cut an access through the exterior of the
house?

For ridgid pipe, I would think exterior access would be the way to go.
You could also use a flexible gas pipe, i.e. corrugated stainless
steel pipe (CSST) or annealed copper.

Of course the point of the original post is that the plumber should
have made sure the notches were not in the middle third of the span.

Wayne

On 6-Oct-2005, Brad Bruce wrote:

How would you install the gas pipe the OP had installed? I guess you'd
have to hang it below the joists....

If you can't hang rigid pipe below the joists, you can get flexible
gas line and run it through holes in the joists.

Mike

"Brad Bruce" wrote in message
news:4j71f.10949$kE5.8075@trndny03...

How would you install the gas pipe the OP had installed? I guess you'd
have to hang it below the joists.... I'm serious. I need to have a gas
line moved in the near future.

Brad

Ask a supplier about "Ward Flex", or "Gas Tite". Generic name SST, stainless
steel tubing. If you can pull a garden hose through, you can get flexible
SST through.
Greg

Not really. The span table that the code official uses will make
the difference. The joists are not 14" apart. They are on 16"
centers - the distance from face to face is 14 1/2".

I don't think your floor is going to cave in, but it has been
rendered sub code. Here is a span table:
http://www.southernpine.com/spantables.shtml
they also have a span calculator:
http://www.awc.org/calculators/span/...izontal%2BSpan

(top posted for your convenience)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep the whole world singing . . . .
DanG (remove the sevens)




"BN" wrote in message
...
George E. Cawthon wrote:

The notch has reduced the effective depth of the joist by the
depth of
the notch. So assume the notch is 1 inch deep the effective
depth of
the joist is 9" - 1" = 8"

If that is a 15 foot clear span (no support except at the ends)
it is
either unacceptable or close to unacceptable depending on the
joist
spacing. Based on my tables you should have 2 x 10's and they
should be
Douglas fir or larch on 16" centers as a minimum. The plumber
should
have put the pipe through holes near the center of the joist.
That
would not reduce the strength of the joist whereas a notch on
the top
or the bottom does reduce the strength



The kitchen is 15' x 10'. The joist span is 15'. There are 6
joists
that are 14" apart. The 1st and last joists are 6" from the
joist-parallel wall. Although there is a double joist 2 feet
from the
wall and one more 5 inches from the double joist. So its a
total of 6
joists spaced 14" apart but starting 6" from either wall plus
the 3
joists I mentioned for a total of 9!

Luckily the double joist is under the cabinet and range side of
the
kitchen. We may put granite or quartz countertop.


Does that change anything?