What type of borer?

[Gooner]

I have ripped out all the plasterboard in my en suite and have found two places where it looks like the timber frame has been eaten by some kind of borer.

My question is, what type?

The affected areas crumble in my hand. There are tell-tale pin holes in the wood and a fine saw dust around the area. The eaten areas can be crumbled to produce the fine dust. (See image).

My internet investigation leads me to believe it is Lyctus Borer, however these type of borer supposedly only eat sap and should not cause "structutal damage". However, the pieces of wood I am looking at sure have had their strength compromised.

Any experts with advice on this one? Do I need to do anything?

Notice that the timber in the image is located directly beneath the shower taps. I am wonder if moisture has attracted these things. The tap holes were not sealed.

Thanks.

[MICKYG]

Gooner

The part affected looks to be the noggin which is attached horizontally, remove and replace.
They would have been in the wood when it was fitted.
Regards Mike

[charlsie]

it looks like it's only one edge of the timber has been eaten which would be the sap wood. you can call them lyctid borer, powder post beetle but yes they only eat sap wood .take the noggin out and replace

[Gooner]

Yep, it is the nogging, and can be easily replaced. However, there is another area in the room where it is on a vertical support.

Also, I am worried that if I found it on two places in one small room, I wonder how much timber has been affected throughout the entire house. :?

[orraloon]

I would replace any bits where they are found. Be glad you do not have termites. Now those beasties can really do a job of demolition in a short space of time. For peace of mind get a pest control inspection done.

Regards
john

[Wongo]

What John said.

Get a pest control inspection done and keep monitoring it yourself for a little while.

[stefoid]

hi, I have damage to two three joists that looks almost identical to this. I bought the house 6 months ago and it looks like existing old damage.

two of the damaged joists are directly over where the previous old coot owner had 'stored' a 2ft pile of used timber under the house. Ive removed that of course. The 3rd joist is about 3m from that area. Cant see any bearers or joists affected other than these three . One good thing the guy did is take off all the boards around the bottom of the house, so it has had exellent airflow recently.

The damage is oragey powder like the photos and the insects seem to have chomped their way completely along these joists from one end to the other without touching the floorboards which are some kind of pine above the two joists and hardwood above the other joist. The floor does not appear spongey directly over the affected area.

So Im thinking lyctids got in at some stage, had a party on the sapwood and have now gone, and I shouldnt need to do anything ?

[Gooner]

Heyya Stefoid,

Since posting my original post, I have found many more areas that have been affected. I am unsure if this is coincidental, but most affected areas involve non-load bearing members. In all cases they have only eaten away no more than 1/4 of cross sectional area and then dissappeared.

I have not had a pest inspector in, and I have not identified 100% what type of borer they are. But I am still assumming that it is "old damage". (I hope). I have never seen any live borer squirming around in affected areas.

One trick that someone at work told me is to lay some newspaper around affected areas. If you start seeing a buildup of sawdust on the paper, then they may still be at work. I haven't tried this myself as I am quite sure that in the places I have spotted damage, they are gone.

In the meantime I keep looking out and inspecting regularly. They have me paranoid.

Would be interested to hear if you get any further information. (What part of Melbourne are you in?)

[stefoid]

I havent been game to dig into the wood, but I suppose theres no reason not to -- If I can strip it by hand then those parts cant be doing much to hold up the floor, can it? But for some reason tearing out strips of joist with your fingers just seems so wrong...

Im in preston and this house was built in the 40s. And the area that is most infected is an add on room so I have no idea who/when it was built, so building codes about % of sap wood probably dont apply either way.

I think I will go digging into the joist and see how much comes away. My money is on lcytids because they havent touched the pine floorboards in the add-on room that are directly above the hardwood joists that have been damaged.

If only part of the wood on one side has been eaten, then that will confirm it, from what I have read.

thanks for the reply.

cheers





Heyya Stefoid,

Since posting my original post, I have found many more areas that have been affected. I am unsure if this is coincidental, but most affected areas involve non-load bearing members. In all cases they have only eaten away no more than 1/4 of cross sectional area and then dissappeared.

I have not had a pest inspector in, and I have not identified 100% what type of borer they are. But I am still assumming that it is "old damage". (I hope). I have never seen any live borer squirming around in affected areas.

One trick that someone at work told me is to lay some newspaper around affected areas. If you start seeing a buildup of sawdust on the paper, then they may still be at work. I haven't tried this myself as I am quite sure that in the places I have spotted damage, they are gone.

In the meantime I keep looking out and inspecting regularly. They have me paranoid.

Would be interested to hear if you get any further information. (What part of Melbourne are you in?)

[stefoid]

just read this "Powder Post Beetle
This lyctid borer attacks the sapwood of susceptible hardwoods, but not softwoods. The female lays her eggs in the exposed end-pores of freshly cut wood, or in a living tree that has been damaged. Borer attack is confined to about the first five years following felling of the logs, or when the timber moisture drops below 20%. The larvae feed along the grain of the wood and never attack the heartwood, so the damage is superficial."

from here: http://museumvictoria.com.au/DiscoveryCentre/Infosheets/10312/

which indicates that the lyctids attack wood from the end and then go along the wood which certainly fits what I am seeing, because only a few joists are affected, but those that are affected are eaten from one end to the other.

Plus everything I have read on anobbid borers is that they love softwood, so if my attack was those guys, my pine floors above those joists would be dust.

phew!

[Gooner]

Stefoid,

I pulled up some more plasterboard in my house recently as part of ongoing renovations. I pulled off the walls and the ceiling. I was in there today having a closer look after re-living my borer paranoia due to you reviving this thread :doh:.

Anyway, I am quite sure what I have (had) is powder post beetle. I saw one! I thought I had a fresh infestation after actually seeing an adult powder post....but I went to grab it and it too turned to dust......*phew too* so it had been dead for a long time it would seem. What I saw is exactly as the image I have attached. (Powder post beetle).

I think that about 1 in 5 of every beam of wood in this particular room has been affected in some way by this pest. Most of it is very superficial, but they sure have had a go. I'm not too worried. I'm sure the damage was done long ago.

[stefoid]

Im definately leaving my joists in place. I cant detect any deflection or anthing that would indicate structural problems, so why bother? Out of sight, out of mind.