raised deck concrete support posts

[lee171181]

Hi i'm building a raised deck & am planning on using concrete support posts as opposed to wood.

What is the best sort of post to use for this as I wanted to use 4x4 posts but can only seem to find 3x3 slotted fence posts! I was thinking of maybe using a concrete lintel instead?

Also can these posts be drilled to allow the fixing of the joists & what is the best way to fix the joist to concrete, - I was planning on using joists either side of the concrete post then some kind of coach bolt right through the middle, bolted on each side? Obviously the fixing needs to be strong with no movement.

Thanks

 

[lee171181]

Anyone got any thoughts/advice on this one? cheers

 

[Khalid1]

Why do you want concrete posts?

The only place I think you could get them is from a company that casts concrete.

100mm x 100mm fence posts dug 600mm down with post crete will give you one hell of a support.

 

[tataylor1]

do u mean like these?

http://compare.ebay.co.uk/like/1510...ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=63&ff19=0

would i use them? no, i know i would use wood.

 

[freddiemercurystwin]

Or sit timber posts in these: http://www.wrekinconcreteproducts.co.uk/item.php?id=14

 

[lee171181]

I don't want to use concrete posts as they are awkward to work with (cut/drill etc) and are not really the right thing for the job but the problem is that the posts are going near a stream and in water so I thought concrete would be the only way as I want it to last & not rot etc.

Digging the holes for the support posts and they are already full of water so I can't see how the wooden posts will last?if anyone has any better ideas I would appreciate it?

 

[freddiemercurystwin]

You could do simple concrete pad foundations and then use 'timber post shoes' (google 'em).

 

[scbk]

What about using more rot resistant timber posts like a hardwood, or larch heartwood?

 

[lee171181]

Would the post still rot if the bottom was completely encased in concrete, ie I mould the concrete around the post so that it comes above the ground so no water touches the post?

Also as the ground around the base is all damp and wet, would concrete around a wooden post prove waterproof?

 

[lee171181]

Anyone know where I could get some large diameter plastic pipe for this job?

I'm planning to use wooden posts 100x100mm, but am thinking of concreting these inside a large diameter plastic pipe to protect from water/rot but just unsure where I could get such a thing?

Would be looking for an 8" diameter pipe minimum, - anyone got any ideas?

Thanks

 

[freddiemercurystwin]

You would get them at a builders merchant, ask for sewer pipe, it comes in various sizes. Really I don’t get it when there are alternatives to sticking timber posts in the ground.

How will you stop moisture seeping in through the concrete from the bottom?

 

[lee171181]

You would get them at a builders merchant, ask for sewer pipe, it comes in various sizes. Really I don’t get it when there are alternatives to sticking timber posts in the ground.

How will you stop moisture seeping in through the concrete from the bottom?

But what is the alternative to timer posts? That's what I've been looking for but cannot find anything suitable!

 

[ntb]

You are over thinking this. More water over and above the timber being damp will not increase the rate of decay. If wood is entirely submerged in water it will actually decay more slowly because the fungi that consume the wood need oxygen to survive. Just use pressure treated fence posts.

 

[freddiemercurystwin]

http://www.toolstation.com/shop/p82691?gclid=CIyY6JPT77YCFVDMtAodwnAAeg
or
http://www.toolstation.com/shop/p75498?gclid=CNzlwbzT77YCFZLKtAodp0EAaA

 

[lee171181]

So what are you suggesting just bolting one of those onto the bottom of a timber post? is that going to make much of a difference? Obviously the bottom of the holes will be filled with hardcore anyway. I was also thinking of using a met post/post spike driven right into the bottom of the hole then the whole lot concreted in.

I just need this to be a strong and reliable solution that will last. Once the post is encased in concrete wont this protect it anyway or will moisture still be an issue?