raised deck concrete support posts

[freddiemercurystwin]

If you use the type of brackets I linked to then the posts are not below ground level. They are bolted to the bottom of the post and these are on top of your foundation. You cast a concrete pad foundation and sit the brackets on top, or the second one I linked to you cast It in place with the concrete haunch up at an angle to prevent the post end siting in water.

The type of concrete you will end up casting will not be waterproof.

Waterproof concrete is for retaining walls or swimming pool walls and the like and is packed with reinforcement. You will not achieve that in your garden.

 

[lee171181]

Ok so I've currently dug 4 holes 1m deep for the base posts. Are you suggesting it will be better (and stronger) to just fill these in with concrete and then fix the timber posts to the top using what you suggest or a post shoe, rather than actually sinking the post into the ground?

I suppose this would eliminate the water & rotting issue, its just whether it will be a strong enough fixing to support the raised deck?

 

[freddiemercurystwin]

Why ever do you think it will not be strong enough? Its a bit of decking not a bomb shelter.

 

[lee171181]

Yes but as its a raised deck I need the supports to be very strong. I just assumed that a post sunk 1m in concrete would be stronger than one bolted into a shoe on top but I suppose either way will be strong enough.

what would you suggest for the foundation? Jus fill it in with concrete? I was going to use postcrete originally due to water but should I be using a mix to provide extra strength? The photo shows how it currently looks with the holes.

Untitled

• lee171181
• 29 Apr 2013
• 1

 

[lee171181]

What type of concrete mix would be best for the foundations for this?

Would ready mix be suitable (& strong enough) or should I be looking at mixing it myself?

 

[freddiemercurystwin]

Just get some ready mix, you're really over-thinking this, there was no need to dig dirty great holes in the first place.

eg http://www.wickes.co.uk/ready-mixed-multi-purpose-concrete-25kg/invt/154142/

 

[lee171181]

the height its being raised above those holes is around 600-700mm, that's why I thought it necessary and am enquiring about the strength of the foundations etc