1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Chestnut posts and concrete...?

Discussion in 'In the Garden' started by VictorDelta, 19 Oct 2019.

  1. VictorDelta

    VictorDelta

    Joined:
    18 Aug 2008
    Messages:
    74
    Thanks Received:
    0
    Location:
    Dorset
    Country:
    United Kingdom
    We're re-placing a garden pergola made of wood which has seen better days. We were advised to use Chestnut poles for the vertical posts as they last longer than other types of wood - so have bought a set of these together with the appropriate number of bags of PostCrete.

    However, we've now been told that chestnut posts are better if just put in the earth rather than using concrete, as the latter tends to make them rot faster (3-4 years v. 15-20 years).

    This was news to us! Has anyone else come across this before?
     
  2. Sponsored Links
  3. Bonni

    Bonni

    Joined:
    11 Jun 2018
    Messages:
    263
    Thanks Received:
    49
    Country:
    United Kingdom
  4. bernardgreen

    bernardgreen

    Joined:
    3 Nov 2006
    Messages:
    22,160
    Thanks Received:
    2,061
    Location:
    Bedfordshire
    Country:
    United Kingdom
    upload_2019-10-19_13-59-49.png

    Free standing on 4mm lead sheet, this photo was taken in 1980 and the timber is still in perfect condition 39 years later. ( the lead was trimmed to the exact size of the post afte the phot was taken.
     
  5. VictorDelta

    VictorDelta

    Joined:
    18 Aug 2008
    Messages:
    74
    Thanks Received:
    0
    Location:
    Dorset
    Country:
    United Kingdom
    Thanks for your replies. However, because this is a rustic pergola, the wooden posts have to go into the ground, with or without concrete round the base.

    My query was really about whether Chestnut - a hard wood - will rot faster in concrete than without...?
     
  6. HERTS P&D

    HERTS P&D

    Joined:
    9 Apr 2010
    Messages:
    8,746
    Thanks Received:
    1,243
    Location:
    Hertfordshire
    Country:
    United Kingdom
    Bernard, was it black and white in 1980?

    :ROFLMAO::ROFLMAO::ROFLMAO::ROFLMAO:

    Andy
     
  7. Sponsored Links
  8. bernardgreen

    bernardgreen

    Joined:
    3 Nov 2006
    Messages:
    22,160
    Thanks Received:
    2,061
    Location:
    Bedfordshire
    Country:
    United Kingdom
    The picture was taken by a photographer who was taking photos for one of the suppliers we used. ( The house was a full DIY self build )

    Wood ( soft or hard ) rots when there is air and damp, wood in water logged ( no air ) soil usually rots much slower than wood in damp soil.

    As regards timber into concrete the rate of rot depends on how much and where damp and air can get to the timber.
     
  9. scbk

    scbk

    Joined:
    22 Dec 2012
    Messages:
    570
    Thanks Received:
    98
    Location:
    Ross-shire
    Country:
    United Kingdom
    Living in the north of Scotland, I've never used chestnut posts*
    Bare in mind Horse and Sweet chestnut are two very different timbers.
    And with sweet chestnut, it apparently makes a big difference if it is summer or winter felled (and also the amount of sapwood).


    IMO timber posts set in concrete isn't a great combination

    If you wanted, you could apply preservative to the posts before they go in the ground.




    *I once built a bench with 4 horse chestnut logs set in the ground as legs, as far as I know it's still there.
     
  10. lostinthelight

    lostinthelight

    Joined:
    11 Feb 2016
    Messages:
    1,553
    Thanks Received:
    271
    Location:
    monmouthshire
    Country:
    United Kingdom
    When timber is referred to as “Chestntnut” it invariably means Sweet Chestnut which is high in tanning and very rot resistant. Horse chestnut by contrast is susceptible to decay so rots easily
    I prefer to ram stone around posts which lets water drain and allows further ramming/tightening if the ground shrinks
    Edit:
    The disadvantage of ramming is it takes a little more time and skill .
     
    Last edited: 21 Oct 2019
  11. Notch7

    Notch7

    Joined:
    15 Sep 2017
    Messages:
    14,655
    Thanks Received:
    1,122
    Location:
    Sussex
    Country:
    United Kingdom
    thereisnt much difference -chestnut will rot in soil and concrete.

    wrap the bit below ground and just a bit above with bitumen flashband or use a post saver
    it can help the posts last 20 years.

    https://www.postsaver.com/

    https://www.toolstation.com/bostik-flashband/p44914
     
Sponsored Links
Loading...

Share This Page