Stump Choices for Restumping

Restumping with steel

There are several different stump types you can use to restump your house. Steel, timber, or concrete are the more obvious ones. Piers and concrete part walls can also be used to provide footings for your elevated floor construction. A combination of materials can be used to restumping a building, although in most cases this is the norm sometimes a combination of materials may suite the construction better.

Timber Stumps

Timber is not so common any more it can be high maintenance and not very versatile for building in under your house. Timber stumps can have a lot of appeal under a semi low or low set house. Farmed and treated hardwood provides straight and long lasting stumps. It can be a good alternative under low block houses especially in areas of high rust or corrosion the stumps can be replaced a lot easier than steel or concrete. Steel has a concrete footing poured around the stump which can be extremely hard to remove without lifting the house. Concrete remains and full stumps are heavy and require mechanical means to remove them in many cases. Timber doesn’t rust so in these situation where they can be kept dry can last extended periods of time up to 30 years.

Concrete Stumps

Concrete stumps are solid and have no movement, with a solid soul footing poured at their base on installation can be very strong and lasting. However depending on the installation can handle little to no sideways movement making them a poor choice in high wind and cyclone areas if they are not treated with care or provided with extensive bracing and certain engineering requirements are met. 

The stumps as with timber usually start at 200mm x 200mm so they are bulky and don’t fit into wall framing readily unless non load bearing blocking, double brick or brick veneer insets are built between the stumps. Weight is an issue and handling expenses from freight to installation have an effect. Concrete stumps have steel reinforcing and this can rust if the concrete cracks for any reason. Concrete stumps have their place and look good as a standalone stump without structure attached or lining a driveway. As with timber they make a great solution when mixed with steel. The centre of the house can be supported on steel while a more bolder concrete stump can line the outside of a house.

Steel Stumps

Steel is by far the most versatile and has become more commonplace being the best choice in most situations. Provided galvanised steel is used, welds are painted and the installation is correct. Some attention to detail is applied where the concrete is mounded up around the stump. This is to allow moisture runoff on the top of the concrete where it meets the steel in the centre. Strength of the concrete and therefore it’s permeability to moisture is addressed. And other engineering considerations derived in the engineering and planning stages are met such as bracing on high-set buildings.

Steel stumps will last in most situations even in the damp and coastal conditions. Provided their installed correctly and made according to local engineering requirements. And they are very versatile in nature, the 75mm x 75mm construction allows them to easily be built into single leaf walls as with timber stud framing and also blocking or bricking. Steel posts allow for easy installation of beams. Removing certain stumps in the centre parts of the building opening up larger areas and making the space more usable.

Other Methods

Piers and part walls are suited to more specialised applications. Once again problem stricken areas may benefit from sections of strip footing and construction from the footing to the underneath of the house in whatever material is more suited. Whereas this becomes a relatively high cost it may not be excessive. If rust or corrosion under your house is an issue then reinforced concrete or brick walls may be the only solution for longevity.

Good Foundations are a Solid Footing

Be sure to check your foundations before you lose your footing

For what may or may not seem obvious reasons it’s very important to maintain your foundations. Restumping and post maintenance in the Whitsundays is always a concern. Proserpine and surrounds have very deep topsoil and a lot of moisture and flooding for extended periods of the year. Bowen like Cannovale and Airlie Beach are constantly open to the weather and also subjected to heavy rainfall. The foundations, the ground, soil or compacted material around your post is of extreme importance. In fact anything within the drip line of your building is of concern. That is any and every part of the ground that is covered by your building is important. Important for many reasons but above all else and for the purposes of this discussion to maintaining the structural integrity of your home.

Foundation Integrity Loss

Two main concerns are in discussion. One is that the buildings posts or stumps lose much of their footings if the soil or material is loosened around the post. The other is water permeating through the subsoil. Extending to the underneath section of the building can and will lead to many problems. Problems such as sinking and or rusting in addition to adding to the aforementioned loss of your footings integrity. In the image shown below it can be seen how any sideways movement that is present be it from everyday wear and tear or storm driven in the case of a cyclone. The buildings movement pushes the solid compacted material away from the stump and it,s replaced with lighter silt aided by driving wind and rain.

 

post movement in a buildings foundations
post movement in a buildings foundations

 

The solution

No water is good water under your house. Keeping the area directly below the elevated section of your building will maintain its structural integrity and keep it strong through the local weather upsets. No water or rain should have access to this section of your building. If there is rain blowing in or some other seemingly uncontrollable case, then you should insure the drainage is such that its immediately taken away. It is by far worth the effort to make sure it can’t penetrate the subsoil.  Although in many cases it’s not a livable component of the building or in many cases not even useful however it needs to be maintained.

Drainage around the house needs to be checked and fixed. Building barriers such as part walls or lattice to keep the rain out. Ground levels under the building to insure good drainage. It can all be readily addressed and will go a long way to the longevity of your home. Some simple materials and building and landscaping up to and under your house. Ideally where the garden stops so do does the weather and also any vermin that can attack the structure of your home.

Post and Frame V Blocking In

Two Story Queenslander

Post and Frame Build in or Brick or Concrete Blocking In

Here we will take a look at the pros and cons of the different methods of enclosing the under story of a high set dwelling. Desirability of material types is one determining factor. A certain look and feel or uniformity top to bottom. If your looking for a rendered look or brick look then the decision should or could be fairly simple. Likewise if its a uniform look from top to bottom then post and timber wall framing is probably the best solution.

Full Restump Post and Frame

One way is to fully restump the building to begin with and then frame in between the posts. Usually with this method there will be some beams installed under the house to remove some of the posts and the ones remaining are designed to fall within wall frames. Some simple planning from the start will insure all the posts are hidden within walls. This method can be done piecemeal provided the posts are installed. The post and beams are the only structural element, the framing and wall sheeting can be done at any stage. Worthy of note, a 3″ block wall could be infilled in between the posts in the case where the posts are already existing or the time frame of the building project is of importance.

Blocking In with Concrete Block or Bricks

With blocking in the process is not quite as simple as the post and frame method previously discussed. However the end result is unquestionably good. There are some posts left or installed under the building with this method. Skyhooks are out of the question and the building needs to be supported. Unfortunately due to the weight of most buildings  the engineering dynamics dictate the need for it to be supported directly under the building. For this reason we install some purpose made posts. These are strategically placed to provide support for the building during construction. And allow us to have the building slightly higher than the level plane for the block work to be installed.

On completion the bracing is removed and the the building is lowered to rest on the block work. Usually 7 or 8 well placed posts combined with support bracing will hold it steady and safe while the blocking work is performed. With only installing 8 out of the usual average of 30+ posts there are many savings. There is far less steel concrete and overall less workmanship. In effect it could be compared to lifting the top half out of the way while you build a bottom story and then place the house on it.  Blocking is certainly more cost effective but not the easiest. Almost everything must be completed before you can safely occupy the building.

Levelling and Replacing posts or Restumping

House on a stump

Levelling Repairs V Full Restump

It’s always better to do something if your building is unlevel. The very telltale’s that inform you of this problem are not the only thing that stands to be damaged. Doors not closing properly, windows jamming, cracks in the wall, rolling floors among the many things that can alert you to the problem. The problems don’t stop there eventually all the symptoms will show. Depending on how long it’s been that way, will impact on the costs to repair your home. Small cracks undetected on the exterior lead to the invasion of the elements and deterioration expedites. This process doesn’t miss anything and gets right into every little detail even rusting bolts and nails holding structures together.

An unlevel structure can put a hold on any renovations. Small things like trimming doors to close in a current unlevel state will come back to you when the structure is finally levelled. New roofs can bend and warp and fixings can be loosened if the structure is not right. Adjusted gaps will have a negative effect when the building is straightened. To top it off it might not go back to how it was due to new work holding sections of it in fixed positions.

In most cases if it’s addressed early enough it is not necessary to restump the building all at once. This is usually only restricted by budget.  And it need not compromise the structure of the building any further if approached sensibly. Levelling it up identifying the worst of the posts and replacing them is often enough to keep the integrity of the structure intact. The rest can be replaced at another time or over time and with a little ongoing maintenance made manageable. Maintenance is the key here. As with anything if it’s preserved it will last much much longer. Keeping your posts clean, painted and pest free and insuring there’s no water pooling around the base or sitting on their tops will extend their life. Keeping your overall costs down into the future.

Highset V Lowset

Old Queenslander Home - Mid Set

Lifting or Lowering Your Home

Among the advantages and disadvantages of going high set or low set with your home or house there are a few that stand out and will make a difference in what you want to achieve. Desirability and practicality play a huge role. Personal preferences will be important to some, investment gains or investment preservation will be of more importance to others.

It could be that you would like to have your home high set to reach a better viewpoint or gain more living space. On the other hand you may desire or require your home or building to be closer to the ground for easier access. Your overall budget may be an influence and the lower building cost an advantage.

Lowering your building in comparison with lifting has a huge saving in the costs of building work. Construction costs are lower both at the time and with any future work you may do. Ongoing maintenance is easier and therefore less expensive.  Direct savings such as less steel in the post construction, less reinforcement and bracing is required. Indirectly there is less handling and therefore lower equipment costs. 

With the increased costs of lifting to a high set position so to does the potential for increased property values. Exceptions to this may be where your home is located in an area with an older population.  People looking to buy in that area are looking for homes to buy with easier access.

High Set

Low Set

Better Views Lower Building Costs
Increased Floor Space Less Maintenance
Increased Property Value Easier Access

 

In the right area the costs of lifting and building in when compared with the final outcome or property resale value can be considerably advantages and in most cases the benefits are well worth the investment.

Many older homes are in a mid set position. This was done to allow airflow under the house to help with cooling. With modern day insulation’s and building methods and materials it has become an obsolete practice. The extra materials used to have it in this location neither high or low topped with an almost unusable space in most cases are not desirable. Investment gains, building and maintenance costs, and accessibility render it impractical to leave or put back without at least some further consideration. There is much to be gained with this transformation.