Do I need to concrete my posts ?

Hello this is my first post and I would just like to say this is a great site. After reading thru the posts I am unsure if I am suppose to concrete the stumps for my veranda or if I can just ram pack the bottom and just fill it in without concrete ? My block which I will be buildin on is on a slope and the posts will be 1.5m high on one side to about 600mm on the other. I am just a bit confused because when I had my house stumped they didnt use concrete and just used soleplates and just backfilled the holes. Any help on this would be much appreciated. Also would it be ok if I just cut the stumps to height after I have set the stumps into the ground instead of getting it right before I fill them in ? I was just thinking of doing it this was because I have very rocky ground and am unsure wat it will be like to work with. Thanks for the help

G'Day Davo,

Welcome aboard! As a new member also, you can spend hours and hours looking for info and everyone seems to have some fantastic thoughts and ideas about any relevant topic you could care to imagine!

Anway to your verandah. You will need to concrete them in! Depending on regulations and heights etc you are going to have to dig some holes (kinda deep ones too!). The last job I did needed 900mm holes and about 300mm diameter. It is generally recommended that some coarse gravel is placed in the bottom of the hole. Set up your string lines, plonk your post in, get in vertical and square, put the concrete in, pump the post a bit to remove airgaps and then brace it in position to ensure it is in the right place when it all sets. I would also recommend a look at using stirrups which is a good way to go for large structures (I think). You set up some form work around the tops of the holes and once the concrete is poured you can then create a slight slope in the top of it, so water doesn't well around the bottom of your posts or stirrups and accelerate corrosion, rot etc.

As for your pole height, get them in then cut them down when your levels are all on the mark. Worthwhile is setting a 'datum' point to work against for the whole structure. Once that is right, all the other posts etc can be trimmed to match. This can even be done after you have added bearers etc.

If you do a bit of a search you will find some good links and advice. Even search under 'decks' as there are some links to sites (can't remember off the top of my head) to the Australian Standards for bearer, joist spacings and sizes too.

My 2c worth, but I am not a qualified builder, so have a good look around.

All the best!:wink:

Gday matt thanks for the help. How much concrete would I need for each stump ? Would a 20 kg bag of the quick set stuff do for each hole ? Thanks

You don't need to concrete them in if they are timber.You said they put a sole plate under your stumps when restumping,so that says to me that they were timber and not concrete.If you are using concrete stumps however, then they need to be concreted in.

Tools

Thanks Tool yes im using pine stumps. So I guess its back to plan A And not to concrete then.

Gday Davo
Depending on how many stumps you have, it may be easier to concrete in some stirrups and set the stumps/posts in to those. It's easier to align a stirrup than a post and because the timber is above ground level, there's little chance of rot.
Of course, it adds to the cost so if you have too many stumps, it may be cost prohibitive!
Hope this helps :)

Not bad if you only want 25 years or so out of your foundations. It's the part of the timber that's near the surface getting wet then dry, that will rot the fastest. Then of course it will be more of a hassle to replace. You'll notice fences always rot the most at ground level, and usually less as they go deeper. Stumping under a house isn't subject to as much weather.

Of course if you elevate it above the ground level on a stirrup, then not only will it last a lot longer, but it will be easier to replace/repair when it eventually does rot.

I should have been a little more clear in that if you are not going to concrete them in, you need to use a sole plate.


Tools