Home |
Search |
Today's Posts |
|
Home Repair (alt.home.repair) For all homeowners and DIYers with many experienced tradesmen. Solve your toughest home fix-it problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
|
|||
|
|||
Joist Notch - Different Issue
If you find joists in the house that have notches cut out of it on top but with no pipes going through it, would it be a good idea to drop in, screw in and glue wood pieces cut to size to fill the notches? I am under the amateur assumption that a 2x10 floor joist holding a load will be under tension at is bottom side and under compression on the top side. So would filling the 1" cube notches on top of the 2x10 joists restore the joist in anyway to 100% of its load carrying capability? Thanks |
#2
|
|||
|
|||
If you are worried about it, fasten a sister board to the notched joist.
But don't use too many fasteners. Each one puts a hole in the joist and that weakens it too. Something else to keep you up at night! "BN" wrote in message ... If you find joists in the house that have notches cut out of it on top but with no pipes going through it, would it be a good idea to drop in, screw in and glue wood pieces cut to size to fill the notches? I am under the amateur assumption that a 2x10 floor joist holding a load will be under tension at is bottom side and under compression on the top side. So would filling the 1" cube notches on top of the 2x10 joists restore the joist in anyway to 100% of its load carrying capability? Thanks |
#3
|
|||
|
|||
Fastening 3-4 foot sister boards on the side is not an option because of
space constraints. BN wrote: If you find joists in the house that have notches cut out of it on top but with no pipes going through it, would it be a good idea to drop in, screw in and glue wood pieces cut to size to fill the notches? I am under the amateur assumption that a 2x10 floor joist holding a load will be under tension at is bottom side and under compression on the top side. So would filling the 1" cube notches on top of the 2x10 joists restore the joist in anyway to 100% of its load carrying capability? Thanks |
#4
|
|||
|
|||
"BN" wrote in message ... If you find joists in the house that have notches cut out of it on top but with no pipes going through it, would it be a good idea to drop in, screw in and glue wood pieces cut to size to fill the notches? I am under the amateur assumption that a 2x10 floor joist holding a load will be under tension at is bottom side and under compression on the top side. So would filling the 1" cube notches on top of the 2x10 joists restore the joist in anyway to 100% of its load carrying capability? Thanks I think if I found some that had been there for a few years I would ignore them and worry about something else. Not sure you expressed it correctly but I agree with your statement that the load on the joists should tend to compress the gap because the force is down. The same principal applies to the other thread in this group. If the plumber cut a 1" notch and placed a 1" iron pipe in it there is no problem. Colbyt |
#5
|
|||
|
|||
"BN" wrote in message ... If you find joists in the house that have notches cut out of it on top but with no pipes going through it, would it be a good idea to drop in, screw in and glue wood pieces cut to size to fill the notches? I am under the amateur assumption that a 2x10 floor joist holding a load will be under tension at is bottom side and under compression on the top side. So would filling the 1" cube notches on top of the 2x10 joists restore the joist in anyway to 100% of its load carrying capability? Thanks I was always taught to NEVER notch a joist. Drilling the middle was acceptable. Notching the top or bottom just reduces the strength of the joist. Your concept of filling in the notches, is not going to do any good in my way of thinking. Best to get a carpenter out and see if there are any real issues. It might be time for a structural engineer. |
#6
|
|||
|
|||
Colbyt wrote:
"BN" wrote in message If you find joists in the house that have notches cut out of it on top but with no pipes going through it, would it be a good idea to drop in, screw in and glue wood pieces cut to size to fill the notches? I am under the amateur assumption that a 2x10 floor joist holding a load will be under tension at is bottom side and under compression on the top side. Professionals have that same "assumption". So would filling the 1" cube notches on top of the 2x10 joists restore the joist in anyway to 100% of its load carrying capability? Depending on how you did it, possibly, but it's simpler and more of a sure thing to sister the reinforcement. Thanks I think if I found some that had been there for a few years I would ignore them and worry about something else. Not sure you expressed it correctly but I agree with your statement that the load on the joists should tend to compress the gap because the force is down. The same principal applies to the other thread in this group. If the plumber cut a 1" notch and placed a 1" iron pipe in it there is no problem. That sounds like you believe that a round pipe in a square hole would restore the strength of the joist. Is that what you're saying? I also need to find out who this plumber is that cuts a perfectly snug notch. Every plumber's work that I've ever seen has been a wood butcher of the highest order. Half-jokingly I tell some of them that on the next job they can run there pipes and I'll frame around them, because after they're done it's what I have to do anyway. R |
#7
|
|||
|
|||
It is sometimes in compression at the top, but it really depends on
where the supports are. Imagine an upright T shape. The ends of the top droop, stretching the top of the joist. Same reasoning applies at the top of the beam near a center post support. -Kevin |
#8
|
|||
|
|||
kevin wrote:
It is sometimes in compression at the top, but it really depends on where the supports are. Imagine an upright T shape. The ends of the top droop, stretching the top of the joist. Same reasoning applies at the top of the beam near a center post support. Which is assuming that the joists are continuous over that center beam, and not lapped, which is the more usual situation. R |
#9
|
|||
|
|||
Yup. RicodJour is right -- there are a couple of assumptions. I should
probably have just left it at "it depends, but often yes" as the correct answer to the question about compression at the top of the joists. |
#10
|
|||
|
|||
"BN" wrote in message ... If you find joists in the house that have notches cut out of it on top but with no pipes going through it, would it be a good idea to drop in, screw in and glue wood pieces cut to size to fill the notches? I am under the amateur assumption that a 2x10 floor joist holding a load will be under tension at is bottom side and under compression on the top side. So would filling the 1" cube notches on top of the 2x10 joists restore the joist in anyway to 100% of its load carrying capability? It certainly couldn't hurt.It probably would do more good if you can "unload" the joists first. How about truss plates? Anyone think they would be of benefit? I've been thinking about this for the bottom of some joists that someone previous notched in my house. Bob |
#11
|
|||
|
|||
On 7-Oct-2005, "Bob" wrote: So would filling the 1" cube notches on top of the 2x10 joists restore the joist in anyway to 100% of its load carrying capability? It certainly couldn't hurt.It probably would do more good if you can "unload" the joists first. The plug would have to be a perfect fit and you'd have to manage to transfer all shear across the bottom of the cube to the joist. That would mean either sufficient screws and/or an adhesive that is both sufficiently strong and a comparable elastic modulus to the wood. If the upper chord is in tension rather than compression, then you'd also have to provide a tensile connection between both sides of the cube and the joist where they contact. It would be easier to sister the joist. It would be easier still to avoid notching the joists in the first place. Why are there so many dumb contractors in the first place? I once had a house where the contractor that converted the house from hot water to forced air heating (decades ago) had cut several joists along one wall to fit 4" ducts! (and then didn't place the ducts there). I had to sister the joists - they had been ignored all those years. Mike |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
OT Guns more Guns | Metalworking | |||
Floor joist sistering question | Home Repair | |||
OT Environmentalists may be in deep Kimchee | Metalworking | |||
more surprises - rotten joist and no lintel! | UK diy | |||
Replacing damaged joists | UK diy |