# Forum Home Renovation Retaining Walls  Retaining wall ideas - Universal beams instead of sleeper posts?

## anotherenovator

Hello all,
i'm building a L-shaped retaining wall at home, it's about 7m x 9m.  To save on costs i want to use timber, but being in an area where there are plenty of termites I'm quite concerned about concreting in upright posts which could be eaten.  Digging those posts out will be a nightmare. 
So what i've come up with is a plan to use galvinised universal beams/columns for the uprights instead or wood.  i've found the size 100 UC15 & 100 PFC (for the ends) which will give me about 85mm clearance on the internal dimension.  The plan is to slot 75mmx200mm sleepers into the uprights.  That way if i have any problems with rot or termites it will only be the cross pieces.  I determine that in the event of rot or termite damage the cross pieces could be cut, removed and then any remaining sleepers above pushed downwards and a new sleeper cut to length and fitted on top.  This structure would also elimiate the need for bolts. 
Firstly, i wonder if anyone has ever done this type of construction before? 
Secondly, if not, does it sound feasable? 
Finally, please let me know if you have any suggestions where i can get these beams, have them cut, galvanised and delivered in Brisbane for a reasonable price?  i know they are not particularly cheap (i need about 10.5m in total. 
thanks very much!

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## Eastwing

This is a very common way to build a wall,  
Tips  
 -Use plastic wedges at the back of the wall and the steel to keep the front face flat 
-Use decking spikes at about 800 centres to keep the sleepers from bowing along the face. 
-Here is a link to a place that will solve all your steel needs and they even have the prices. Scott Metals - Products: Beams

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## anotherenovator

> This is a very common way to build a wall,  
> Tips  
>  -Use plastic wedges at the back of the wall and the steel to keep the front face flat 
> -Use decking spikes at about 800 centres to keep the sleepers from bowing along the face. 
> -Here is a link to a place that will solve all your steel needs and they even have the prices. Scott Metals - Products: Beams

  
Thanks, Eastwing! appreciate your tips and link!!  i'm a total novice at this stuff and work all day indoors hence the following potentially stupid question;  would you kindlyplease tell about the decking spikes (nails??), i'm not quite sure how to use them to keep the sleepers from bowing.  Do you mean drive them into the face of the sleepers?  do they fasten two surfaces together?  
thanks again.

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## Eastwing

Use the decking spikes (really big nails) to nail one sleeper to the next. 
1 One your posts are in place drop your bottom sleeper into the steel channel
2 use a packer between the concrete and the base of the sleeper to achieve a level sleeper.
3 once this is level use plastic wedge between the back of the sleeper and the steel (available from bum-rings) two each end
4 Drop next sleeper in above last use wedges again.
5 drill a holes in the top edge of the sleeper and hammer in a 250mm decking spike.
6 repeat till done 
The wedges are to stop the sleeper from twisting and the spikes are to stop the front face from bowing out of alignment. in a 2.1 long sleeper I would drive a spike 300mm from each end then one in the centre if the wall is more than two high move the spikes a few millimetres so you don't try to drive one into the other.

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## anotherenovator

> Use the decking spikes (really big nails) to nail one sleeper to the next. 
> 1 One your posts are in place drop your bottom sleeper into the steel channel
> 2 use a packer between the concrete and the base of the sleeper to achieve a level sleeper.
> 3 once this is level use plastic wedge between the back of the sleeper and the steel (available from bum-rings) two each end
> 4 Drop next sleeper in above last use wedges again.
> 5 drill a holes in the top edge of the sleeper and hammer in a 250mm decking spike.
> 6 repeat till done 
> The wedges are to stop the sleeper from twisting and the spikes are to stop the front face from bowing out of alignment. in a 2.1 long sleeper I would drive a spike 300mm from each end then one in the centre if the wall is more than two high move the spikes a few millimetres so you don't try to drive one into the other.

  
Thanks mate, real good info.  I'm pretty sure i understand what you mean now!  ready to tackle this job as soon as i get the universal beams cut, galvanised and delivered.

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## rrobor

Retaining wall about 7 ft high  near me where they used H beams. they didnt nail or anything, just slotted the sleepers into the groves.

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## Eastwing

> Retaining wall about 7 ft high  near me where they used H beams. they didnt nail or anything, just slotted the sleepers into the groves.

  Yeah and you can buy new cars without air con, but do you want one? 
I have been a builder for a while now and I used to just drop them in I have found a much better way through experience. I'm not saying you need to do this. You will finish up with a much better product for only a few dollars more, why would you not?

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## Chumley

Eastwing, 
I notice the shortest stock length on those beams is 9 metres.  If you wanted a retaining wall a metre high and buried about a metre in the ground you'd obviously cut them into 2 metre lengths.  If they were hot dip galvanised to start with could you seal it properly using a paint on galvanised coating or a galvanised spray?  Or would the moisture eventually get through and rust the beams? 
Curiously,
Adam

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## Belair_Boy

Pre-galvanised lengths can be obtained for this very purpose.
If termites are a problem, why not go for a solid concrete panel. 
Friends retaining wall on his ICF house build. Solid precast concrete panels with a nice stone look.  No termite problems here.

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