How to use Postcrete

21 Comments

  1. Kevin Nolan

    Can I use postcrete to install sleepers as fence posts with the dimensions 2400 x 200 x 100
    buried 600 into the ground with a 300 diameter round hole? If so how many bags do you suggest?

    Reply
    • Olga Waterhouse

      For your particular use we would suggest 4 bags per post, this will ensure the hole is completely filled with Postcrete, and should
      reduce the chances of the posts ‘slipping’ over time under the weight of the sleepers and any soil they may be retaining.

      Reply
  2. j wilson

    I am installing a 240cm ×10cm fencepost.
    how much postcrete do i use?

    Reply
    • Olga Waterhouse

      With a 240cm x 10cm post typically 60cm will be below the ground, the width of the hole would be 30cm.
      2 bags of Postcrete will fill the hole approximately half full, once the post is level you can backfill the hole and compact it.

      Reply
  3. Keith

    I am installing a 5cm square post how deep and how big an opening

    Reply
    • Olga Waterhouse

      Typically for a 5cm (2.5 inch) post the minimum hole width would be 15cm (6 inches), so you would need a narrow trenching spade or a post hole / split shovel. The depth is dependent on the height of the fence (post) required above ground, as a guide a minimum of 1/3 of the above ground height should be below ground e.g. if the post has to be 180cm (6ft) above the ground 60cm (2ft) should be below the ground.

      Reply
  4. C Jordan

    How long do you have to wait before you can hammer nails in postcrete?

    Reply
    • C Jordan

      I mean how long before you can hammer nails into posts set in postcrete?

      Reply
      • Olga Waterhouse

        Good question, we suggest a panel can be hung in as little as 10 minutes using Postcrete (weather permitting of course).
        There is a good technique for nailing in to a vertical post, if you start the nail as normal with a couple of light taps and then hold a second hammer or in fact anything heavy (a brick works well for example) in constant contact with the opposite face of the post to where you are nailing, this simple action will reduce the vibrations or wobble in long posts and make your job of nailing the panel or panel clips far easier with less force needing to be exerted through the post with the hammer… Alternatively you can screw the clips or panels to the post, this way you can take them down if you ever need to without damaging them.

        Reply
  5. Alan CARDWELL

    I’m using 3-inch posts with 6ft above ground and 2ft below. How wide should the hole be, please?

    Reply
    • Olga Waterhouse

      Thank you for the question, typically the width of the hole should be three times the width of the post; so in your example the hole would need to be 9″x9″ (22.5cm x 22.5cm). This may be a little narrow to dig with a standard spade so if you have to do lots of posts it could be worth investing in a ‘split shovel’ or narrow trenching spade.

      Reply
  6. Russ

    Can I drill a fixing into post crete to secure deck post foot plate as I have used post crete to create strong flat base on uneven soft ground.
    Thanks

    Reply
    • Blue Circle Products

      Thank you for your question.

      Although we are aware of Postcrete being successfully drilled for fixings, Postcrete has been designed and formulated specifically for the erection of fencing and smaller gate posts to be embedded within the material; as such, we would not consider it to be the best option for your particular application.

      Assuming speed is one of your primary concerns, best practice would be to use our Extra Rapid Cement (https://tarmac-bluecircle.co.uk/product/extra-rapid-cement/) mixed with an all in ballast. The lager aggregate of the ballast (typically upto 20mm) reduces the chance of cracks forming while drilling the holes and/or tightening the fixing(s). Concrete made using Extra Rapid Cement will provide an excellent long term durable solution in your particular application while still gaining strength considerably faster than a concrete produced with a conventional cement.

      I hope this information helps.

      Kind regards

      Reply
  7. Dave

    Hello, I am building a kids climbing fort and using 10cm x 10cm x 360cm posts. The hole to bury them in is 30cm x 30cm x 120cm.
    How many bags to you suggest per post this seeing as these are the supporting legs of the climbing frame.
    I take it if takes 4 bags you fill the hole with 4xWater then all 4 bags at once, you don’t wait for one bag to set before layering in the next bag on top?
    Also do you recommend filling the holes to the top for extra support or is back filling the top 1/3 of the hole with soil okay?
    Thank you

    Reply
    • Blue Circle Products

      As best practice we would not suggest using Postcrete for a child’s climbing frame as there is no guaranteed compressive strength – it is ideal for supporting fence posts and smaller gateposts.

      We would suggest using your High Strength Concrete instead which is guaranteed 40N, again ready to use just add water but is not fast setting and normally takes 2-3 hours to set. Based on measurements given you would need just over 11 bags per hole.

      Kind regards

      Reply
  8. Alex Knight

    Would postcrete be ideal for setting 150mm x 150mm green oak posts into the ground for a gazebo?

    Reply
  9. Howard

    I’m building a slightly raised deck over an old rockery to put a greenhouse on. How deep a hole should I dig for the posts?
    Thanks

    Reply
    • Blue Circle Products

      Hi Howard,

      We would not suggest using Postcrete for this project as there is no guaranteed compressive strength. It is ideal for fence posts and smaller applications such as small gateposts and rotary lines however not to support sheds or similar structures. In this instance we would suggest our Multi Purpose Concrete or High Strength Concrete. Both are ready to use however not quick setting like Postcrete (normally 2 -3 hours)

      The size of the hole is dependent on the posts but would suggest narrow and deep with approx 25% of the post below ground.

      Reply
  10. terry bryan

    hi – i am assuming i can use this for traditional purposes? I have some left and need to fill in a narrow ‘hole- in an internal floor before covering with carpet. This OK to do?

    Reply

Submit a Comment

Your email address will not be published. Required fields are marked *