# Forum Home Renovation Decking  How many stumps?

## mattsalamonsen

I am planning to build a deck abour 5m x 4m.  it will be at ground level and attached to the house.  i will excavate out .3m or so of dirt beneath the deck.  How many stumps do I need?  some manuals say every 1.2-1.5m, otheres do not specify. 
Also, cement treated pine stumps directly into the ground, or use stirrups? 
thanks, 
matt

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## 2x4

Depends on your bearer sizes to the amount of stumps you require. But you could work it the other way if you wish.
So....if it was 5mtr along the house and you used 4 stumps ( on each bearer )your bearer size would have to be around a 125x50 uns hwd f14
If useing only 3 stumps ( on each bearer )a 175x50 uns hwd f14. 
What size joists are you using.......need to know this one to work out the number of bearers, then you can tally up the quantity of holes you need to dig.

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## skot

Use stirrups...especially if your area is prone to termites

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## mattsalamonsen

Thanks for the tips. 
I am flexible with the sizes of joists and bearers, but would like to minimise the number of stump holes i have to dig. 
The joist and bearer sizes recommended by Bowens, where I will probably buy the wood, are 90x70mm (bearers) and 90x45mm (joists). They recommend 1.5m between bearers and 1.2m spacing of stumps along each bearer. I would be happy to buy larger size joists or bearers to minimise the number of stumps. and suggestions? 
thanks, 
matt

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## skot

You could increase the span of the bearer from post to post @2400 and the distance between the run of bearers to 1800 thus increasing the bearings to 125x75 and joists to 100x50. 
Have a look at the tables below...it is a juggling act to get the bearers, joists and spans

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## 2x4

> Use stirrups...especially if your area is prone to termites

  
I'm not sure that it would make a differance in this situation. Termites will make their galleries over anything.
Since there will be no access under the deck for visual inspection,does it really matter?
Just make sure you use pine treated for inground use.

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## Bloss

If the deck can be on the ground (you said you were going to excavate 300mm) you can place H4 or H5 bearers directly on the ground and you do not need stumps or stirrups. Or you can use concrete blocks or pads rather than stirrups which are often easier and quicker for low decks. Plenty of posts already describing how. As for termites - use TP or HW or be prepared to use termite treatments for untreated HW.  :2thumbsup:

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