Termites

[Julia]

This is a reminder to not get complacent about having termite check done regularly and the termite barrier around the house replaced regularly.

I let two years go by since the last termite inspection (which gave the all clear) and the pest control person has just told me there are termites in front half of the house, affecting all window frames and quite possibly the timber framework in the walls.

Have no idea of cost of replacing all this, but obviously it won't be cheap.
Damn! plus a few more expressive curses!

So keep up the regular checks, folks - they'll be a lot cheaper than the alternative.

 

[kincella]

on tv last week...CA or the FRi night house and garden on ch 7....they said it would cost about $4000 to replace the inside of an ordinary 3 bdr house...so it is cheaper to have the inspection done every 12 months....
I can guarantee that the builders would charge far more than that in the real world, remove the plaster etc, repaint, replace all the timber....
they aslo stated that garden mulch is the worst thing to have near your house.....relayed that to an aunt, who ,because of the drought , has been mulching everywhere...to protect whats left of the garden....
oh and some people think because they have a brick house its not a problem..
and I know of people who would not buy a timber house for that reason...
thinking it cannot happen to a brick house

 

[Julia]

Yes, I have a brick house. But there is mulch on garden bed adjacent the affected walls, though last time I checked the weep holes were still clear.

 

[Stan 101]

For anyone building a new dwelling it is imperitive to ask for H3 treated pine trusses and frames. There is the option of a Light Organic Solvent Preservative (LOSP) or one of the derivatives.
The cost is approximately $160 per cubic metre + the cost of untreated radiata / slash pine and gives real piece of mind.

The treatment is safe and is pyrithium based. Apparently safe enough to eat.

cheers,

 

[Prospector]

Oh Damn, Julia, that is bad news.

A friend of ours realised after some time that her house had termites. Badly. Especially in one of her son's bedrooms, right in the wall where his bed was. It was so badly eaten away that they could be heard munching! So she asked him if he had heard anything (he was maybe 8 years old) and he said yes, he could hear all this noise going on in the wall so he put his ear muffs on to hide the noise to sleep! How long for, she asked. Hmm, I dunno, a few weeks!

She had to replace all her timber floors (they had eaten underneath, just leaving a thin veneer) as well as timber and woodwork to three bedrooms and bathroom.

Are you near a creek by chance?

 

[prawn_86]

For anyone building a new dwelling it is imperitive to ask for H3 treated pine trusses and frames. There is the option of a Light Organic Solvent Preservative (LOSP) or one of the derivatives.
The cost is approximately $160 per cubic metre + the cost of untreated radiata / slash pine and gives real piece of mind.

The treatment is safe and is pyrithium based. Apparently safe enough to eat.

cheers,

Why not steel frames?

 

[Green08]

Western Red Cedar is resistant to termites. Beautiful colour, on the expensive side and if you have the pull up windows and don't turn the lock first you will knock a piece of timber off. Ouch

Sorry to hear of your problems Julia hope there is a relatively viable opion for you.

 

[Stan 101]

Why not steel frames?

There are numerous issues with steel frame.

1. Corrosion. You need to trust all welds, rivets and cuts of the steel section have been adequately treated. I'm yet to see one steel frame / truss house installed correctly. Fixing to the steel frame is via tek screw (self drilling). This creates swarf and bare steel areas ready for corrosion. Likewise, holes need to be drilled through noggs and studs for electrical and plumbing. Those holes are never treated with a corrosion inhibitor.

2. Fire. A standard section 90x35 pine can be charred 10mm around the whole envolope and still retain it's ability to withstand all dead loads (the weight of plaster, roof tiles, solar hot water system and the like). Apply heat (no need for direct flame) to steel frame c section and it loses it's tension and compression properties and fails catastrophically.

3. Fixings. Adding fixings such as shelving and the like are a much easiler with a more positive connection.

4. Noise from expansion and contraction.

5. Easy site rectification with timber (and they are required more than you will ever know. Having the head height (bottom of lintel or sill) incorrectly manufactured is a minor inconvenience for a timber frame. It is a major **** up in steel.

5. Timber is a plantation product and comes from sustainable reforestation. It locks up carbon (the latest catch cry on everyone's lips) where as the manufacture of rolled steel is the devil in this regard.

6. It's a misnomer to think steel frames stop termites. They simply travel over the steel to the tasty architraves. The bottom plate of the steel frame can often hold moisture that attracts termites and have them nesting in the cavity between the brickwork and the internal plasterboard.

That's a nice start... I would never purchase a steel frame based on years of industry knowledge and onsite inspections.


Cheers,

 

[quinny]

affecting all window frames and quite possibly the timber framework in the walls.

Yes, I have a brick house.

I am not entirely familiar with building structures but how come you say you have a brick house, yet you have a timber framework in the walls?

I am just wondering. Do they build up the brick around the timber?

 

[Stan 101]

Do they build up the brick around the timber?

Traditionally on the east coast of Oz, yes. It is referred to as brick veneer framed housing. Generally you will find a 110mm of brick, a cavity (empty space) of 40-50mm and then either a 70mm or 90mm frame cladded with plasterboard, fc sheet or the like.

 

[awg]

good chance the termite inspection missed the prob 2 yrs ago.

I have taken to doing these myself, after finding some myself once

called the termite blokes and they were too fat and lazy to crawl into the tight space that the termites were, they never would have been found with a quick inspection. they even gave me a mouthful, so I sent them away, and dealt with the problem myself

the best way is to use a VERY bright light and inspect EVERY possible spot were they can build a covered mud tunnel, from the ground, which they MUST do.

If u search your underfloor area like this every 6 months, you should be ok.

NO WOOD should be in contact with the earth. (they will bore up the middle)

I realize u r a lady, but this is one u can manage IMO, u will get dirty and have spider webs on u, if u do it properly

really bad problems come about, if additions or modifications have been made that mean the termites have invisible access to woodwork...I have seen this, ie timber houses that have been bricked up...the only way forward is internal wall removal


they usually tunnel up in a very concealed, damp spot.

they are all through the soil, eating organic matter, and always try to come back.

the electronic meters they use wont pick up an early tunnel.

very strong poisons are needed to eradicate them, and it only lasts a while.

used sump oil soaked into the ground, around a wooden item will deter them (old-fashioned solution), not so sure the EPA would like that now.

having said all that, u will need builders and termite sprayers to rectify now, unless u r very handy with the tools.

termite traps can be bought to show the presence

 

[quinny]

Traditionally on the east coast of Oz, yes. It is referred to as brick veneer framed housing. Generally you will find a 110mm of brick, a cavity (empty space) of 40-50mm and then either a 70mm or 90mm frame cladded with plasterboard, fc sheet or the like.

Thankyou Stan 101.

 

[Glen48]

There is another system were PVC pipes are placed under the slab and you are suppose to get some one out to pump more product into the system.. shame they banned Arsenic. I have see W. Ants going up the outside of a Brick wall heading to the Ceiling. Moisture is some thing else they like.

 

[Aargh!]

I am not entirely familiar with building structures but how come you say you have a brick house, yet you have a timber framework in the walls?

I am just wondering. Do they build up the brick around the timber?

It's a common misconception that people think they're safe as the exterior of their house is brick while being unaware that the brick is purely there as a facade and provides no structural integrity other than transferring wind load to the timber frame.

Both timber and galvanised steel construction have their advantages and disadvantages. Termite proof timber (timber soaked in nasty chemicals) offer great protection from the critters. I have questioned the ability to resist them when saw cuts are made to construct the frames/trusses but have been told they still wont go near the stuff.

Galvanised steel isn't as bad as made out. Corrosion is not so much of an issue as the gal can provide protection to the exposed steel in close proximity. Steel needs to be heated to over 200 deg C before it starts to lose is strength. It doesn't fail catastrophically either, you do get some warning (through excessive deflections) that it's about to come down. Timber will just collapse.

A timber section common to house construction such as 70x35 and 90x35 can not carry loads if charred 10mm around its perimeter. The inherent factors of safety to allow for the inconsistencies in timber approximate to the timber to maintain its strength when it maintains over 70% of its cross sectional area.

Not all of this is applicable to all situations as it depends on the sections role in the structural system.

 

[Prospector]

So are double brick houses (ie no timber internal walls) safer?

 

[Aargh!]

So are double brick houses (ie no timber internal walls) safer?

Well depends....

Double brick walls are resistant to termite attack however if there are timber roof trusses I've seen termites scale these to get a feed.

Double brick walls offer better thermal resistance to fire however the roof would still collapse, which wont provide lateral stability to the walls and they would then fall over.

So it's a system as strong as its weakest part. The walls hold up the roof while the roof holds up the walls!

 

[Stan 101]

It's a common misconception that people think they're safe as the exterior of their house is brick while being unaware that the brick is purely there as a facade and provides no structural integrity other than transferring wind load to the timber frame.

generally that is correct unless one is using a Rock block or similar.

Both timber and galvanised steel construction have their advantages and disadvantages.

Agreed.

Termite proof timber (timber soaked in nasty chemicals) offer great protection from the critters.

pyrithium can hardly be referred to as a nasty chemical. If you are referring to CCA, that hasn't been used for treatment to H3 for eons. It is still used for H5 treatment for inground timbers.
Could you shed some more light on these chemicals you speak of?

I have questioned the ability to resist them when saw cuts are made to construct the frames/trusses but have been told they still wont go near the stuff.

H3 treatment is a full penetration treatment. End cuts offer the same ability to repel as the dyed edge. I think you may be referring to the old style, early LOSP H2 treatments that were only an envelope. They were traditionally cut to length and angle, strapped then dipped in the solution, left to dry and then assembled.
The dye used in treated timber is simply that. It has no bearing on properties of the timber, except it's slipperiness which can affect nailplate bite.

Galvanised steel isn't as bad as made out. Corrosion is not so much of an issue as the gal can provide protection to the exposed steel in close proximity.

Not from our findings.

Steel needs to be heated to over 200 deg C before it starts to lose is strength. It doesn't fail catastrophically either, you do get some warning (through excessive deflections) that it's about to come down. Timber will just collapse.

True. Create an environment where excessive defection is on a girder's bottom member (in tension) with an average 12 kilo newton dead load @ 900mm centres and tell me that won't end in a catastrophic result. With excessive deflection in the bottom chord, the top chords will be forced into excessive buckling sending the truss out of plane. Once that starts, restraints can't hold and down she comes. I can offer you a 3d animation offered to the coroner of such an example.

A timber section common to house construction such as 70x35 and 90x35 can not carry loads if charred 10mm around its perimeter. The inherent factors of safety to allow for the inconsistencies in timber approximate to the timber to maintain its strength when it maintains over 70% of its cross sectional area.

You aren't taking into account other factors incorporated in the truss / frame design. I just ran the comps on a 9m span truss bottom chord and the member passed under dead load as did 2335mm stud with a restraint at 1350mm.


But I get your points.


Cheers,

 

[awg]

So are double brick houses (ie no timber internal walls) safer?

yes, usually, cause both brick courses are usually on a concrete slab, with no wood ties at ground level, so the termites dont get in.

Termites NEED water, so they MUST have a connecting tunnel to the ground.

If there is a possible point of ingress below ground, or poor maintenance, termites can penetrate brick courses, or even concrete, and get into the roof trusses, so you should inspect them as well.

same deal as underfloor, bright light, check everywhere, get very dirty.

 

[Aargh!]

generally that is correct unless one is using a Rock block or similar.


Agreed.


pyrithium can hardly be referred to as a nasty chemical. If you are referring to CCA, that hasn't been used for treatment to H3 for eons. It is still used for H5 treatment for inground timbers.
Could you shed some more light on these chemicals you speak of?


H3 treatment is a full penetration treatment. End cuts offer the same ability to repel as the dyed edge. I think you may be referring to the old style, early LOSP H2 treatments that were only an envelope. They were traditionally cut to length and angle, strapped then dipped in the solution, left to dry and then assembled.
The dye used in treated timber is simply that. It has no bearing on properties of the timber, except it's slipperiness which can affect nailplate bite.




Not from our findings.



True. Create an environment where excessive defection is on a girder's bottom member (in tension) with an average 12 kilo newton dead load @ 900mm centres and tell me that won't end in a catastrophic result. With excessive deflection in the bottom chord, the top chords will be forced into excessive buckling sending the truss out of plane. Once that starts, restraints can't hold and down she comes. I can offer you a 3d animation offered to the coroner of such an example.



You aren't taking into account other factors incorporated in the truss / frame design. I just ran the comps on a 9m span truss bottom chord and the member passed under dead load as did 2335mm stud with a restraint at 1350mm.


But I get your points.


Cheers,

OK, if you want to start spinning numbers you will have to put it specific about the situation you are referring to.

You refer to a timber girder truss loaded @ 900crs (I assume it's carrying perpendicular trusses) with point loads of 12kN. Now this must be a concrete tiled roof with large spans? Span, pitch, ply's, restraints (battens and steel strap) all play a role in the top chords restraint. Web ties as well. I don't need a 3D animation, I've designed these things before and have a good knowledge of how they work. I've also experience in steel design. If you want a fire proof/termite proof house build a concrete box, 100mm cover to steel 40MPa would do it.

What do you mean I'm not taking into account other factors? My last comment reads "Not all of this is applicable to all situations as it depends on the sections role in the structural system.".

You say you just run the comps on a 9m truss. A bottom chord is in tension, not bending, not compression (unless under a wind event) so what has restraint centers got to do with it? Axial tension stress is simply load/area, nothing to do with slenderness or second moments of area...

You're telling me a stud with 30% of its cross-sectional area and exponentially reduced slenderness will be sufficient? I'm highly scepetical and curious.

 

[Aargh!]

yes, usually, cause both brick courses are usually on a concrete slab, with no wood ties at ground level, so the termites dont get in.

Termites NEED water, so they MUST have a connecting tunnel to the ground.

If there is a possible point of ingress below ground, or poor maintenance, termites can penetrate brick courses, or even concrete, and get into the roof trusses, so you should inspect them as well.

same deal as underfloor, bright light, check everywhere, get very dirty.

The brick course is on slab in brick veneer construction. Same boat in this regard.