Checking your house stumps
Restumping & Foundation Specialist
Houses with timber floors built more than 30 years ago will mostly have their floors supported on timber stumps. The life expectancy of these stumps can vary from 20 to 50 years depending on the type of timber, soil conditions and external influences such as surface drainage and insect attack.
In the course of inspections, DJ Baker and Son has found that up to 30% of timber stumped homes investigated needed immediate re-stumping either partially or completely.
Before undertaking renovation work on older homes, it is essential to check the condition of the stumps. Many people have watched in dismay as newly completed alterations have been virtually destroyed as the structure subsides.
In brick houses, where the bearers are supported on brick piers at the ends, rotten stumps will cause a “trampoline” effect in the centre of rooms. Contrary to popular belief, the condition of the stumps in weatherboard homes cannot be definitely confirmed by jumping on the floors.
If the stumps have rotted evenly, the floors may appear firm, however they will almost slope away from brick fire-places. Other symptoms are crooked door and window frames.
It should be remembered that these symptoms are only evident after the stumps have failed completely. A house may appear quite sound during a visual inspection, but could start to sink shortly afterwards if the stumps have just reached failure point.
The condition of stumps can be ascertained by scratching away 50mm to 100mm of soil from the base of the worst stump to check its condition below the ground.
Stumps deteriorate most quickly in wet conditions and generally the worst stumps are those with the highest and most prominent water marks.
If only a few appear faulty, individual replacement may be the best solution. However, if more than 20% to 30% of stumps show serious deterioration, total re-stumping should be considered.
Bulky sub-floor heating ducts can often hamper proper investigation of stumps and supporting walls. Walls and stumps are sometimes removed when ducts are installed, without it being obvious, leading to structural problems.
If you care contemplating installing central heating, restumping should be considered prior to installation.