# Forum Home Renovation Pest Control  Borer holes or something else?

## Watters

I've been getting the shower recess ready to take a new compressed fibre cement floor when I noticed holes in two areas on a bearer (hardwood). The holes look black. Are these borer holes or something else? I've put green Ecoseal timber preservative over the hole areas, hence the stain marks on the bearer. The building was built in 1989 but I've no idea how long these holes have been there. There is no sign of frass or mud tunnels.

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## Watters

Here's a photo of the bearer before I put the ecoseal on it.

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## mudbrick

Could they have been there before the timber was cut? When I've seen borer holes before they are round and go straight in not angled like the long black ones on the left.

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## Watters

> Could they have been there before the timber was cut? When I've seen borer holes before they are round and go straight in not angled like the long black ones on the left.

  Possibly, hard to know. This is directly below where the yellow tongue chipboard shower floor was (before I removed it) which was damaged due to failed fibreglass waterproofing (1989). So the bearer (and joists) in the vicinity of the shower floor would have got repeatedly wet. Suppose I should put termite insecticide on the bearer and joists a metre either side as a precaution.

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## Optimus

Where exactly are we looking???

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## Watters

> Where exactly are we looking???

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## OBBob

There's not enough resolution to see more than a fuzzy black dot. I thought you get more of a concentration of holes?

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## Bloss

These would have been there from when it was milled - there is no dust or other evidence. Just go ahead and build . .

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## Marc

Mm ... looks like the stomping grounds of a mutation of Forficula Auricularis on the turps, ergo the multiple entries and exits.  :Smilie:

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## r3nov8or

Forgive the levity, but they couldn't be old skew nail holes by any chance? 
*runs away*

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## OBBob

> Forgive the levity, but they couldn't be old skew nail holes by any chance? 
> *runs away*

  That's what I thought too.  
*runs away as well*

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## METRIX

> Mm ... looks like the stomping grounds of a mutation of Forficula Auricularis on the turps, ergo the multiple entries and exits.

  Marc, you never cease to amaze us with your in-depth knowledge of the most obscure subjects, well done. 
Would you suggest to remove all the bearers and replace with something resistant to Forficula Auricularis as a safety measure ?

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## OBBob

> Marc, you never cease to amaze us with your in-depth knowledge of the most obscure subjects, well done. 
> Would you suggest to remove all the bearers and replace with something resistant to Forficula Auricularis as a safety measure ?

  Like steel?   :Tongue:

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## Marc

> Marc, you never cease to amaze us with your in-depth knowledge of the most obscure subjects, well done. 
> Would you suggest to remove all the bearers and replace with something resistant to Forficula Auricularis as a safety measure ?

  Absolutely remove all the holes and replace with un-holy timber. Forficula is a nasty beast particularly when it mutates due to turps abuse...  :Smilie:

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## METRIX

> replace with un-holy timber.

  
Perhaps an Exorcism might help ?

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## intertd6

> I've been getting the shower recess ready to take a new compressed fibre cement floor when I noticed holes in two areas on a bearer (hardwood). The holes look black. Are these borer holes or something else? I've put green Ecoseal timber preservative over the hole areas, hence the stain marks on the bearer. The building was built in 1989 but I've no idea how long these holes have been there. There is no sign of frass or mud tunnels.

  nothing much to worry about there in the way of destructive insects, I'd be more worried about the bearer hanging off the side of the brick pier, it should be centrally located on it.
inter

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## Marc

Well spotted. Providing the bearer was not moved sideways by the force of the Forficula attack, it can be fixed easily by 
A) lift the whole house and replace the bearer for a new one in the correct position.
B) Place a sister bearer to take the weight of the joist

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## Watters

> nothing much to worry about there in the way of destructive insects, I'd be more worried about the bearer hanging off the side of the brick pier, it should be centrally located on it.
> inter

  Seriously now, thanks for the constructive input. Yes, the bearer is not central although it isn't as off centre as it looks in the photos. Even the following photo shows it being more off central than it is due to the camera angle, but the bearer is off central, true. When I was under there doing the blocking I felt this pier move slightly behind my back when I was leaning against it. When I took a look above I saw that this pier had no packer between it and the ant cap. So the bearer had an air gap beneath it above the pier! I have now wedged a piece of fibro in there. If you look carefully at the earlier photos you will see a bright shadow where a packer must have been originally placed between the bearer and the ant cap. Someone must have either removed it at some point in history or it had worked its way loose somehow I guess. 
Hopefully it will be alright though. It's not furniture.... 
Regarding destructive insects, I have sprayed Bifenthrin insecticide on the bearer. 
Presumably the bearer not being supported here might have contributed to movement of the bathroom floor and the subsequent cracking of the floor tiles at a more remote location of the bathroom floor? For the main part of the bathroom floor (excluding the shower recess which is now CFC) the floor will be covered by James Hardie Ceramic Tile Underlay. Page 9 of the James Hardie installation instructions for tile underlay calls for 50mm by 50mm galvanised mesh in the screed, no doubt this will stiffen things even further. Not sure where I will get the 50mm by 50mm galvanised mesh from though, anyone?

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## Marc

Yep, no need for sister joist, all good. The mortar in the pier must be cracked and without proper load you can move it a bit. Nothing to worry about. It's not perfect but nothing you can do about it short of rebuilding the pier. That must be the neatest toilet rebuild I have ever seen. Did you vacuum? 
I am glad that you take my jokes well.  :Smilie:

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## Watters

> Yep, no need for sister joist, all good. The mortar in the pier must be cracked and without proper load you can move it a bit. Nothing to worry about. It's not perfect but nothing you can do about it short of rebuilding the pier. That must be the neatest toilet rebuild I have ever seen. Did you vacuum? 
> I am glad that you take my jokes well.

  Cheers. No vacuum, broom, dustpan and brush, goes back to my days working on sites with Taylor Woodrow. Tidying up after each stage is as important as doing the work, at least that is what I was repeatedly told. Ahh, the days of old, stacking bricks in a British snow blizzard, brings back memories. 
Shower CFC is in place, next step is to remove the b1t## fibreglass from the YT and then I will be into tile underlay mode. Be good to get past the fibreglass removal. Now, where did I put the Flexovit grinding disk...

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## Bloss

Clean up as you go is the go . . . not so sure about the exorcism for earwig infestation!  :Rolleyes:  But getting on the turps is always a reasonable option - whatever the problem . . . 
The cracked tiles will not be due to that one pier and the slightly off centre bearer, more likely just overall structural movement due to reactive clay soil. BCA has been amended to take reactive soils into account since 1989, but they are always a problem - thats why properly designed & constructed 'floating' slabs are the preferred choice.

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## Marc

Well ... now that you mention it, I did not make the connection between the previous thread and this. So the cracked tiles happen to be just above a pier that was away from the bearer and not taking the load. Interesting. Well, you packed it now, that should even out the load and stop the bearer from flexing.

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## Watters

> ...more likely just overall structural movement due to reactive clay soil. BCA has been amended to take reactive soils into account since 1989, but they are always a problem - thats why properly designed & constructed 'floating' slabs are the preferred choice.

  Interesting, the villa was built in 1989. Sadly, a floating slab is not an option. 
I have stopped water from strong rains from getting under the house which is what used to happen. Hopefully that will stop any expansionary tendancy of the clay in the subfloor but I guess it is a lottery. 
I can only hope that putting down tile underlay on the stripped back yellow tongue chipboard, waterproof using stretchy rubber membrane (Crommelin Wettite), screed with a 50mm x 50mm galv mesh, more waterproofing, then finally tiles (a little bit smaller than the old ones) put down with Monoflex tile adhesive will provide a better outcome for the floor than the way it was before. Also floor flanges will be installed for the vanity and toilet pipes (there were no flanges in the old arrangement) and better puddle flanges (Wondercap) will be installed for the shower waste and main floor waste. Oh, and no more fibreglass either.

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## METRIX

Be careful if your going to grind the new flooring for puddle flange, these product have high content of Silica, ground up it's just as bad as the big A.

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## Pendejo

I know quite a lot about borers; I have a lot of experience with them. Those holes are not furniture beetle holes (aka borer or woodworm). Hope this helps. 
The black discolouration suggests perhaps the powderpost lyctid beetle. 
In any event, bifenthrin is a good choice.

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## Watters

> I know quite a lot about borers; I have a lot of experience with them. Those holes are not furniture beetle holes (aka borer or woodworm). Hope this helps. 
> The black discolouration suggests perhaps the powderpost lyctid beetle. 
> In any event, bifenthrin is a good choice.

  Thanks for that, it helps to get an idea of what caused this. The bearer is hardwood but when I saw that the bearers are a pale colour I suspected that they are sapwood and not heartwood, unfortunately. The holes would seem to confirm that they are sapwood. There seem to be only two separate local groups of holes. I will ring the holes with a Texta pen so that I can see if any new holes eventuate although the Bifenthrin should have given the bugs more than a headache. I also have a couple of green cap cans of Ecoseal so I might also do a couple of squirts with as well. I'll also shine a torch around to see if there are any other signs elsewhere although I didn't notice before.

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## Marc

:Rofl5:  Now we are getting "experts in borers" ... For God sake Watters, those holes existed when the wood was milled and did not happen under your house, I was joking about the forficula, surely you could see that. 
 I am an expert...  :PANCAKES:

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## Spottiswoode

I'm not an expert, but the holes looked too regularly spaced to be natural to me. They look to be like where some packing was stapled around the timber or something.

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## Pendejo

> Now we are getting "experts in borers"

  Why does that amuse you? Just because someone else knows more than you about something is not a good reason to sneer at them.  :Doh:  
Watters, enlarging your area of concern, it appears the holes are evenly spaced, which could denote human source

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## Watters

> Why does that amuse you? Just because someone else knows more than you about something is not a good reason to sneer at them.

  Thank you for saying that. There has been a bit of unconstructive jollies at times.   

> Watters, enlarging your area of concern, it appears the holes are evenly spaced, which could denote human source

  And thank you also for that input as well.

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## Marc

Watters, the holes have human source, so aliens can be discarded as the culprits. 
(I thought that should diminish your area of concern rather then enlarging it ?)
Must be the Chilean wine.

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