New shed termite protection

[Kingfisher]

I'm getting towards the final stages of the new shed. It's 12m x 7m steel framed and colorbond clad. Roof is insulated with Sisal and walls will have fibreglass batts with fibre cement sheet lining. Floor is concrete with no apron outside.
So nothing here to be eaten by white ants, but the benches and cupboards against the walls will be timber, and having lost a bench to the little buggas some years ago I would like to stop them getting in.
The shed sits on red sand in the mallee near Morgan SA and the white ants here are very active.
I remember some years ago building an extension on the house the ex now owns and we laid a copper pipe along the join from old house to new extension prior to pouring the new slab. The pipe had holes drilled every ??mm and was encased in a fabric sleeve to stop dirt blocking the holes. One end was blocked off & the other rose out of the ground adjacent to the front wall of the house. So every time the house is treated, chemical is poured into the pipe and leaches into the soil. Quite simple I guess.
So I wondered about putting a similar pipe around the shed with a riser at each corner to fill with nasty stuff.
Any thoughts about this system?
Has anyone experience with similar?
Or recomendations for something totally different also welcome.

[rod1949]

So was treatment applied to the soil before the slab was laid?

[TermiMonster]

Probably a bit late now, but a slab laid to AS is itself a termite barrier. Therefore, with forethought in design, you can often avoid the need for other (expensive) barrier/chemical systems.
Assuming all slab penetrations are protected, if the perimeter of the slab is left visible for a minimum of 50mm clear all the way around, and regularly monitored for mud tunnels, (and that is usually much easier for a simple shed than a house) you have a termite protection system.
Obviously, there are many designs where this is not possible, but it is handy to know.
TM

[Kingfisher]

The concrete was poured after the build, and does not extend externally beyond the walls and there was no soil treatment prior to building.
A lot of other works are still ongoing including a verandah with paving on one side, tanks on another, possibly a wood shed on a lean to (although asking for trouble here !!).Combined with ever shifting sand it seemed pointless to treat under the slab, when the perimeter is the weak point.
It may have been a poor decision but that is where I am.

[appiwood]

Termimonsters comment about the slab complying to AS ( Australian Standard 3660.1 ) and being deemed to be an effective barrier needs to be commented on - the slab can easliy be made to be termite resistant by having the concretor vibrate the concrte as it is placed. My obverstaion is concretors don't like to vibrate the slab because the air is vibrated out = more concrete ( since they normally quote a job the less concrete they use the better ( for them ) ) they have to have " someone " using the tool o vibrate the concrete, " someone " has to be paid so again more cost ( to the concretor and the tool has to be hired or paid for, same thing. If you see boney concrete when the forms are removed then you can see how termites can enter through the slab.

Ed

[jimbur]

I never expected termite problems in my shed but.........
I had a wooden drilling jig under the lathe and when I went to use it found it was just a shell. They'd come in through an expansion joint so it's probably wise not to put susceptible timber anywhere near a joint or a crack and not to have places you can't see. Of course when the buggers are hungry all timber is susceptible eventually.
Cheers,
Jim

[Kingfisher]

Snap!!
I had a timber work bench in the middle of a shed suffer the same fate some years ago. They came through the expansion joint that time too.
Mark.

[maitreya]

yer i agree with most of the people above.
keep antyhing timber away from any joins in the slab and even better keep wooden benches away from the edge of the slab as well.
Termites will have to come over the slab edge to eat timber or through small cracks or joins in the concrete

[ch!ppy]

The concrete was poured after the build, and does not extend externally beyond the walls and there was no soil treatment prior to building.
A lot of other works are still ongoing including a verandah with paving on one side, tanks on another, possibly a wood shed on a lean to (although asking for trouble here !!).Combined with ever shifting sand it seemed pointless to treat under the slab, when the perimeter is the weak point.
It may have been a poor decision but that is where I am.

the woodshed/lean to is definitely not a good idea, your shed is a sizeable investment so you should protect it, even though its steel contruction, keep clearance around it..paving up to edges of the shed can be a problem as well if it is too high a level ,ideally it should be 75mm below the sheds concrete slab so you have a visual of any mud tunnels coming up the edge of the slab and entering your shed, this is the same mistake countless people make on their homes as well, i couldn't count how many times i see brand new homes built and a few months later the owners pave up, level (or higher) to the house slab, it creates an entry point for the termites and is against the code, people either arnt aware of it or ignore it, quite often people dont like the small step up to the house but its there for a reason.

unfortunately sheds often arnt built to the same standards as homes (even though a large percentage of sheds get used as recreation areas, extra bedrooms or granny flats etc they arnt meant to used as such so the code, council/gov, shed companies dont take it as seriously. the company that sells them as a matter of routine put the paper work through council without the council giving it a second look and quite often a relatively unskilled worker or team come and erect it, just so long as its up, looks ok to owner and done for the right price is par for the course.

as such there are often weak points or entry points for termites to enter. ideally you want the slab poured at the same time they concrete the columns/posts/uprights (whatever you want to call them) in, because the concrete is a good barrier provided no sizeable cracks develop (about 1mm is generally considered good enough to let termites in, a decent slab with adequate steel should resist cracking). say the columns go into the ground 300mm (some might be more or even twice that but often only 300mm) then the concrete should go at least 400mm or more and should be vibrated so absolutely no gaps around the columns are present (the termites crawl up the gaps). some shed installers will rest the columns on the ground before concreting in which is not good, columns rust although will often take decades before it causes a structural problem but is an entry point for termites.

because many people don't have the money to start with or the shed installers don't know or care the floor doesn't get poured until a later date, even though the columns were concreted in. assuming the slab is well made and doesn't develop cracks, is 75mm above (you can get away with a bit less) the surrounding ground and below the zinc/colourbond exterior cladding, then the only entry point will be where the posts/columns are (they can often crall up between the floor slab and the pier of concrete that the columns are sitting in, then up the column into the wall cavity (assuming you have lined the shed, if left open to air then they wont usually come up, they hate breezy fresh air and hate the light), of course if you happened to have a perfect seal around the columns/posts then your in luck but its not always the case

if you havnt got the ideal construction, as many people dont, then its advisable to make inspection hatches where each column is, you can check them once or twice a year , clean or spray some poison around them

if you havnt got some sort of clearance around the outside edge of the slab, 50mm at least, then dig the dirt out and lower the height of it around the outside, if you dont then your asking for trouble particularly if timber is used in the walls, if you can keep the area dry around the shed (paths, concrete or paving) it will help, termites love moisture so run overflow from downpipes or water tanks away from the building.

the above measures are best so you wont need the copper pipe scenario to poison and even if you did want to poison you could spray and let it soak down but if circumstances arnt ideal and you really want to do it, still dont use copper pipe, its just a waste of your money and a valuable resource nowadays, you could use PVC pipe and even hook up the compressor to it after you have filled it with poison to force it into the ground, this system provides a barrier but remember its not fool proof, they can still go under or around a barrier.

if you have cracks or other entry points on the interior then you can drill many holes along the area and force poison down them (fill them with concrete after), if you have enough coverage then it will provide protection in only that spot for 5-10 years when you will need to do it again. you can also protect the shed in another way by putting bait stations around the perimeter (a few feet away) of the building (no poison near them), when you see termite activity in them you apply the poison (different stuff to what you use to spray), the termites eat it or get it on their exoskeleton, take it back to the main nest and it kills the whole nest...this system costs a fortune from the termite companies but there is a bloke up Qld that sells all the stations, poisons etc needed for a fraction of the cost..the idea with this system is to give them something they like to eat before eating your building, once you see them you bait them and they kill off the nest

there are some measures to help fix problems that shouldn't be there to start with, but hey, thats what happens more often than not. ideally before starting the floor the foundation (dirt) should be sprayed with poison-gives around 10 years protection, use the orange plastic under the concrete, it has a poison impregnated into it, stops moisture rising as well, pour columns with floor slab in one go, slab 75mm above exterior paths, exterior cladding about 75mm clear of paths as well (you should be able to see the slab sides)

cheers
chippy

[Kingfisher]

Thanks chippy. I should have researched this before the floor was poured The paving advice makes sense so I will make sure to check on that and probably spray as well.
Mark

[ch!ppy]

Thanks chippy. I should have researched this before the floor was poured The paving advice makes sense so I will make sure to check on that and probably spray as well.
Mark

oh well, s tuff happens as they say...doing the best you can with what you have is all you can do

inspection hatches in the walls (particularly in the corners and near the columns) are a worthwhile measure as well, especially since you haven't yet lined the inside of the walls they can be easily incorporated on the inside (bit harder on the outside but they are out of the way out there), gives you peace of mind to be able to check and an access point to spray without tearing down the whole wall...as many ways to do them as your imagination allows, section of wall that unscrews, or place a chair rail around the wall and the panel below the chair rail detaches,
or custom made very high skirting out of colourbond that unscrews or put a very high timber skirting, if you use meranti (rather the modern mahogany replacement-i forget whats its called atm) termites dont usually eat it, they dont like it for some reason, if you use pine they will eat it but hey, it will leave some tell tale mud creeping into the room that can be a early warning signal

cheers
chippy

[nrb]

When I had our house built the termite guy said if you put some small boxes buried in the ground around the perimeter of your house and put offcuts of Oregon in them,open up regularly to see if you have any termites,if none you most likely be OK,if you do find signs get someone in.
He said that as Oregon has a strong scent and termites love it and will give you some indication before they get to you.

[ch!ppy]

When I had our house built the termite guy said if you put some small boxes buried in the ground around the perimeter of your house and put offcuts of Oregon in them,open up regularly to see if you have any termites,if none you most likely be OK,if you do find signs get someone in.
He said that as Oregon has a strong scent and termites love it and will give you some indication before they get to you.

yeah, basically thats the fundamentals of a exterior bait system, also like the one the guy in Qld sells , difference is his are purpose built with light traps, their cylinders instead of boxes, have slots in them to allow easy access, plastic so durable, have some sort of thick cardboard liner that serves a couple of purposes), a small viewing window which is a key point, with a window you dont have to open the station to see if there has been activity, opening and closing the boxes can easily disturb them (the termites) in the early stages and they wont (may not) come back which makes the station , well no good i guess, if you do see activity then you mix up the bait which comes in a powder form (so it last years) into a thick paste to form a soft fruit bar type texture, place it in the station, they eat it (gets on their exoskeleton rather) and take it back to the nest which destroys them at the source...Oregon is good i know from experiance, many of them use an aussie hardwood, oak or ash i cant remember exactly atm, they like that as well but its more durable than the softwoods in the damp ground..i have installed that system a few times for clients and found it to be good, far better price than getting the big companies in if your into DIY, they charge hundreds just to come out and inspect the stations once a year, many of them dont use a window either so they disturb the termites or put down human scent from fingers when inspecting..i had one client that had these around his house and the big company were inspecting them often, they didnt wrk at all because they were disturbed, i had to fix the guys house which cost him about $30 000, he didnt even get me in to do that job specifically, but 5 min after i walked in i said you have termites, lots of them too, he said, cant be, we have inspections twice a year, inside and outside..i can tell you the guy wasnt too happy with the company!

chippy