Search the forums

Loading

How much joist damage is too much?

JohnT8's picture

Just wondering if anyone has a guideline on when to replace a termite damaged joist? 


2x10's spanning nearly 16'.  I'm leaning towards replacing just about any of them that show any sign of having been chewed on just to keep a future home inspector from freaking out.    But was curious if there was a guideline from a structural point of view?


 


 


jt8


"Talent is God given. Be humble. Fame is man-given. Be grateful. Conceit is self-given. Be careful."  -- John R. Wooden

jt8

Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
-- Carl Sandburg

(post #69644, reply #1 of 12)

If you can see damage, there's more than you can see. Replace them.

I think that's too long a span for a 2x10, anyway (unless maybe they are on 12" centers). Much less with damage.

Life and suffering are inseparable.   


"Doubt is not a pleasant condition, but certainty is absurd."

~ Voltaire

(post #69644, reply #4 of 12)


If you can see damage, there's more than you can see. Replace them.


Seems like the house has had two different groups of termites.  One group ran along the surface, and didn't seem to like the inside of the wood.  They chewed the surface of the wood and made mud/sawdust tunnels everywhere they went.  The other group was just the opposite and tended to run inside the wood.  Group #2 was much more destructive.  Push your prybar right through the 2x


I think that's too long a span for a 2x10, anyway (unless maybe they are on 12" centers). Much less with damage.


That is what I think.  For that span I'd rather see 2x12's.  But this is the house that used to have a 6x8" main beam (3 2x8's), so not surprising that they've maxed out the joist span.  2x12's won't fit as replacement joists short of notching the ends.


I've considered putting in secondary beams (2 2x12's on 16 ton jack posts) to cut the joist spans in half in high load areas, but haven't run it by the engineer yet.



jt8


"Talent is God given. Be humble. Fame is man-given. Be grateful. Conceit is self-given. Be careful."  -- John R. Wooden



Edited 12/27/2005 5:04 pm by JohnT8

jt8

Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
-- Carl Sandburg

(post #69644, reply #5 of 12)

For those that missed the other thread.  Here's  a pic of the old 6x8 beam that was replaced in the 34-ish year old house.


As I mentioned in the previous reply, there were two batches of termites that went through the house.


Group 1:  Travelled extensively throughout the house, but did mostly surface damage.  They were wiped out years and years ago.  Bugman commented twice that he was suprised at how extensive they had travelled without doing much damage.


Group 2:  Existed in about 3 places in the house.  They didn't travel much, but brought destruction everywhere they went.  Hitting the main beam and portions of the sill and rim joist.  They were wiped out a couple weeks ago.


Group 2's travel route was invisible except at entry/exit points (end of joist/beam)...but you sure knew they were there when you pushed your prybar right through the wood like it was tissue paper.


Group 1's travel route was marked by tunnels along the outside of the joists/studs.  They liked the paper on the back of the drywall and insulation, but don't appear to have penetrated very far into the 2x's (of the pieces I've removed so far). 


Do termites not like freshly cut lumber?  Maybe the first group came in shortly after construction.  I don't know.


jt8


"Talent is God given. Be humble. Fame is man-given. Be grateful. Conceit is self-given. Be careful."  -- John R. Wooden

jt8

Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
-- Carl Sandburg

(post #69644, reply #7 of 12)

Termites LOVE wood that has been softened up a little for them, like if has gotten wet alot and has some fungus on them.  It's like a termite appetizer.  I had those same two kinds in my house too.  Those surface paper eating ones are more annoying than destructive.  They will make dozen of pinholes in drywall ceilings and keep raining crud down.


The interior ones are really bad.  Try whacking each and every joist you can reach with a hammer claw.  You should be able to find any that are damaged enough to need replacing.  You should also check for sure the sizing on those spans.  If those joists are just the minimum, then ANY termite damage is basicly reducing your rating below acceptable.  If this is the case, then just sister every other one and be done with it.  I would also spray it with a Borate solution to help keep them away.


Think about gassing the house at least every 10 years.


Rebuilding my home in Cypress, CA


Also a CRX fanatic!

YAY!  I love WYSISYG editing!  And Spellcheck!

____________________________________________________

(post #69644, reply #8 of 12)

>   Those surface paper eating ones are more annoying than destructive. 


Those may be silverfish, not termites.  They go after paper.


> Think about gassing the house at least every 10 years.


Look around for fresh frass from drywood termites, and mud tubes built by subterraneans.  Look for swarming drywood termites, and where they're coming from.  If a neighbor has real bad drywood swarms, it may be cheaper to give him a fumigation than to keep tenting your place every few years.  Look at trees and utility poles, they get termites, too.  Even live trees. 


 


 


-- J.S.


 

 

 

-- J.S.

 

(post #69644, reply #12 of 12)

Termites LOVE wood that has been softened up a little for them, like if has gotten wet alot and has some fungus on them.  It's like a termite appetizer.


House had been vacant at LEAST the last 5 years.  About two winters ago, a water pipe froze and filled the crawl and probably about 6" of the first floor.  Apparently it took a few days for a neighbor to notice the windows were fogged up and thought that was odd for a vacant house in Feb.   That is probably what helped draw the second group of termites in. 


I've referred to this one as the 'mold and termite palace'.  I've been demo'ing the house for over a month.  Filled a 20 yard dumpster the first week.  Been working on filling a 40 yarder.  All the wall drywall and insulation is gone.  The ceiling drywall is gonna go, just trying to get some other stuff done prior (cuz I lose the heat when I yank the ceiling).  Crawl insulation is going.  Subfloor is gonna go, and I'm changing part of the floorplan, so some of the interior walls are going bye-bye.  Kitchen is gone.  BA's will be gone.  Yanking/replacing the plumbing and electrical. 


Think about gassing the house at least every 10 years.


I had the full treatment from the bug guys.  They came out and trenched around the house and put chemicals in.  Then trenched around the crawlspace perimeter.  Then trenched around all the support posts.  The 5 year guarentee covers future treatment as well as covering any damage.  And it can be extended for $100-ish per year.  Bugman says they've never had the termites return in a house they've treated with whatever the heck chemical they used (made by Bayer I think).


But I planning on being clear of it prior to the 5 years being up.



jt8


"Talent is God given. Be humble. Fame is man-given. Be grateful. Conceit is self-given. Be careful."  -- John R. Wooden



Edited 12/28/2005 10:29 am by JohnT8

jt8

Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
-- Carl Sandburg

(post #69644, reply #2 of 12)

Rather than just "replacing" the joists, why not just sister all of the existing joists that have been damaged with new joists? Only reason I could think of not doing it that way would be that you want to dispose of all the evidence of the little guys.

(post #69644, reply #3 of 12)

The house will sell with a terminte guarantee, so we're not concealing the fact that it had them.  I just don't want to go out of my way to advertise the damage.


 


jt8


"Talent is God given. Be humble. Fame is man-given. Be grateful. Conceit is self-given. Be careful."  -- John R. Wooden

jt8

Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
-- Carl Sandburg

(post #69644, reply #6 of 12)

I agree, the best idea is to sister rather than replace, unless the old joist is so far gone that it lets go of the nails attaching the subfloor to it. 


I've had some sole plates that I literally demoed with nothing but the shop vac.  And there was a time I hit my head on a joist in the crawl space and had two thoughts:  1.  Hey, wow, that didn't hurt.  2.  Oh S--t.  The whole joist is gone from termite damage. 


Ideally, the new joist provides the strength to support the vertical load, and the remainder of the old joist serves to attach the existing floor to the new joist.  If you can't do it that way, you have to be very careful not to eff up the floor attaching it to the new joist. 


 


 


-- J.S.


 

 

 

-- J.S.

 

(post #69644, reply #9 of 12)

I would not use a 2x10 to span 16' to begin with, so any damage whatsoever would be a good excuse to replace them, maybe even with 2 x 12

 

 


Welcome to the
Taunton University of
Knowledge FHB Campus at Breaktime.
 where ...
Excellence is its own reward!

 

 

Oh Well,

We did the best we could...

(post #69644, reply #10 of 12)

With the exception of Grade #3; 2 X 10 joists 16" OC are allowed by the 2000 IRC to span 16 feet in residential sleeping areas with a live load of 30 psf. In living areas with a live load of 40 psf, southern pine is approved for a 16 foot span except for grade #3. Allowable deflection is L/360.


I am not saying this is good building practice but it does meet code.


You are pretty close to the span limit for the joists and most certainly should sister the damaged joists. You have to make sure the damaged joists have sufficient integrity to sister.  Those that do not should be replaced.

(post #69644, reply #11 of 12)

I would not use a 2x10 to span 16' to begin with, so any damage whatsoever would be a good excuse to replace them, maybe even with 2 x 12


Simple 32x49 (outside dimensions) rectangle footprint.   In the crawl, the main beam runs across the middle of the house, cutting the 32' in half.  The joists are sitting on the concrete block foundation on one end and the main beam on the other end.  The only way I could squeeze the 2x12s in as joists would be to take a chunk out of each end so that they sit flush with the remaining 2x10's.  Do you think a 2x12 with the ends notched is any better than a 2x10?


I had been thinking that the shorter way 'round the barn' would be to add some 2x12's parallel to the main beam, thereby cutting the joist spans to around 8'.    Haven't nailed down the sequence completely, but was thinking: 1. yank subfloor up 2. replace joists needing replacing (w/ 2x10s) 3. make concrete pads (maybe 24x24x9") every 12' or so  4. jackpost on each pad to hold up a couple 2x12's.


The proposed new utility room (furnace, water heater, front loader w/d) and MBR (I like waterbeds) would be the first candidate (they are next to each other).  LR/K would probably be the next.


But I'm waiting to toss that idea to the engineer until I've got a couple other things to add to it.  If I'm gonna pay for an 'hour', I want something that is going to take him more than 30 seconds to answer.



jt8


"Talent is God given. Be humble. Fame is man-given. Be grateful. Conceit is self-given. Be careful."  -- John R. Wooden



Edited 12/28/2005 10:25 am by JohnT8

jt8

Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
-- Carl Sandburg