# Forum Home Renovation Sub Flooring  stump height for termite inspection

## manofaus

I know that the minimum height from the ground to the bottom of the bearers is 400mm (for termite inspection reasons), but upon talking to the council they say that there is an exception somewhere in the BCA in reference to the height of the bearers. Could any body look this up in the BCA for me? My bearers are 300mm (4.0 span) to on which sits 240mm (3.3 span 400cts) I joists. Any chance I could drop it a little lower then the 400mm, that way the verandah is even lower to the ground?
thanks ever so much.

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## intertd6

> I know that the minimum height from the ground to the bottom of the bearers is 400mm (for termite inspection reasons), but upon talking to the council they say that there is an exception somewhere in the BCA in reference to the height of the bearers. Could any body look this up in the BCA for me? My bearers are 300mm (4.0 span) to on which sits 240mm (3.3 span 400cts) I joists. Any chance I could drop it a little lower then the 400mm, that way the verandah is even lower to the ground?
> thanks ever so much.

  Just going off memory you can go down to 150mm around the edges for a distance of 2m, another alternative is to run your joists into the bearers & use joist hangers off the side of the bearers, that way the top of the bearer & joists are the same height & you have gained the depth of the bearer.
regards inter

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## ringtail

I'll have a look tomorrow. BCA in the van. :Tongue:  Inter is right though. From memory it only has to be 400 mm if termite inspection is required and 150 mm within 2 mt of the house sounds familiar if the timber is treated. I think there is something about the type of ground too - over a slab or other sealed surface you can drop the height. Its all about moisture / sub floor ventilation / termite. But I'll confirm tomorrow

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## shauck

> I'll have a look tomorrow. BCA in the van. Inter is right though. From memory it only has to be 400 mm if termite inspection is required and 150 mm within 2 mt of the house sounds familiar if the timber is treated. I think there is something about the type of ground too - over a slab or other sealed surface you can drop the height. Its all about moisture / sub floor ventilation / termite. But I'll confirm tomorrow

  From BCA
(1) 400mm clearance required only where termite barriers are installed that need to be inspected (see Part 3.1.3); and 
(2) On *sloping sites* the 400mm clearance required by (1) may be reduced to 150mm within 2m of external walls in accordance with Diagram b. 
Interestingly tho 
Building a House. Framing Practices (Simpson and Hodgson) 
"However, when particleboard sheet flooring is to be used the clearance _between the flooring and the soil_ must be no less than 400mm" 
I couldn't find back up info on this through CHH PDF. It only reiterated BCA pretty much.  
That book is a text book so you'd hope it was correct.

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## ringtail

Beat me to it Su.  Did you have a bludger Friday ? :Biggrin:  :Biggrin:  :Tongue:

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## manofaus

ok thank you lads. does this only apply in the habitable part of the dwelling? I would think that it would not apply to the verandah and deck.

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## ringtail

Timber is timber as far as the BCA is concerned. I wish they would make the distinction between habitable and non habitable but alas........

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## shauck

> Beat me to it Su.  Did you have a bludger Friday ?

  Sure did. Rain, rain, rain. Played around with the new washing machine, getting it set up/level and reading the minefield of an instruction manual.

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## ringtail

> Sure did. Rain, rain, rain. Played around with the new washing machine, getting it set up/level and reading the minefield of an instruction manual.

  A woman's work is never done..... :Biggrin:  :Biggrin:  :Tongue:  :Tongue:  :Tongue:

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## shauck

> A woman's work is never done.....

   :Hahaha:

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## Bloss

> Sure did. Rain, rain, rain. Played around with the new washing machine, getting it set up/level and reading the minefield of an instruction manual.

  What's an "instruction manual"?  :Wink:

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## ringtail

> What's an "instruction manual"?

  
I was going to venture down that road but thought better of it  :Biggrin:  :Biggrin:  :Biggrin: . (secret men's business)

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## manofaus

so ringtail all decks and verandahs must have 400mm between the bearers and the ground for access?

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## ringtail

> so ringtail all decks and verandahs must have 400mm between the bearers and the ground for access?

  No, not necessarily. The way I interpret the BCA is, the clearance can be as little as 150 mm provided access for termite inspection (if required) is there. If there is a gap between house and deck (say 30 mm for termite inspection) there is no reason why you couldn't use H4 or treated timber or DC 1 sitting directly on the ground. If the deck is attached to the house its a different storey. These pics give the perfect example. With this deck I had to cut the block. I laid a small slab with the concrete left over from the post holes to lock the retaining wall in. The clearance to the slab is only 2.5 bricks. But because its a slab and not dirt there is no moisture issue. In the second pic the bearer attaches above the ant cap. The ant cap can be inspected from the outside and from underneath but with less than 400 mm clearance this is still perfectly legal. The timber is H3 LVL.

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## intertd6

Just a point to remember, generally provisions for termite protection only need to be used on structures with a structure that is susceptable to termite damage, so if you build out of something that can not be eaten by termites you could be able to skirt some of your issues
regards inter

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## manofaus

ah excellent. I never would have thought of it like that. The verandah will be lower then the floor level of the house and the joists will be hung from the house bearer. Then the bearer at the front of the verandah (which will support the joists will be less then the 400. But what you are saying is that I can go as low as 150 at the bearer at the front of the verandah because the house bearer is at the standard of 400. Fantastic. Thank you.

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## ringtail

Should be fine. I assume the joists at the house will have the same protection as the original house bearer ( ant caps or similar). The front bearer really only needs the standard 75 mm clearance front natural ground level the same as timber posts. This is the confusion with the BCA - it makes general statements. You can get more clearance at the front by using joist hangers. That way the bearer is lifted up the depth of the joists. The only issue is, can you get under the deck to inspect the house ant caps ? If there is no way to do that you will have to screw the first few boards so they can be removed - although you are probably screwing the decking down anyway...right ? :Biggrin:  
Of course the other option is to run another bearer 400 mm off the house and leave a 25 mm gap between decking and house. If you use H3 / H4 or DC 1 timber having the bearer 150 off the ground ( or less) is no issue that I can see.

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