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Different Stumps For Building

When it comes to the overall structural integrity of your home, one serious factor is the home foundation. Thus, it is best if you consider the merits of steel stumps vs. concrete stumps for building. The same holds true both for any home renovation or rebuilding process. The tradition has been to use timber or concrete stumps with timber bearers. However, with recent advancements in construction site processes and techniques, concrete slabs and galvanized steel are now used for foundations.

Continue reading to learn more about available options for types of stumps and foundations, determining factors, deterioration, and maintenance.

Factors Determining The Type Of Foundation

Your choice of foundation type may depend on several factors.  A few merits of using concrete slabs vs. timber or concrete stump foundation are also included:

  • The site location, soil type, and topography
  • The style chosen for the building
  • The preferences of the owner
  • The cost of building


Note that using concrete slabs for building houses provides higher energy ratings. This is due to the excellent insulation provided by the concrete. A house built on stumps usually needs good insulation in the subfloor for an acceptable energy rating.


You may decide to use concrete slabs due to their ability to reduce noise transmission. This holds true between different levels or different rooms of the same level of a house.


A concrete slab foundation is usually less costly than timber or concrete stump foundations. Why? The reason lies in the higher labour costs in constructing the stumps and framing the subfloor. Moreover, you would need more insulation and cladding materials for the extra height stumps.


Concrete slab foundations are often regarded as more fixed, less susceptible to movement, and with an infinite lifespan.

Factors Leading To Stump Deterioration

Soil can shrink and swell over seasons. In addition, the soil directly under the building can remain dry since it is covered. Thus, any rain only falls on the edge stumps. Consequently, the perimeter stumps tend to sink further than the internal stumps, with gravity as the culprit.

Other causes of stump deterioration include wear and tear of the stumps, poor drainage, leaky plumbing, and insect damage.

Building On A Concrete Slab

Simply put, slabs are large solid expanses of poured concrete. Typically, they contain reinforcing materials like steel mesh and reinforcing rods. You can use concrete slabs within a subfloor and floor structure. Other flooring finishes can be laid on top, or you can include the top floor finish. The design and thickness of concrete slab can be different based on the building requirements.

Concrete slabs are commonly used for flat building sites. This is because when used on a slopping site, the cost is a lot higher. In addition, concrete slabs are often used in major renovations and extensions. Interestingly, concrete slabs can be incorporated even when the original building does not have them.

For example, during extensions, slab-on-ground or suspended slabs can be used. Similarly, a concrete slab may replace the timber during the renovation of rooms with timber floors. It ends up improving the insulation.

Building On Stumps

This type of foundation involves having a sub-floor of horizontal bearers (beams). In turn, these beams support joists. Joists are small close-spaced beams that support the flooring material. There are stumps on which the horizontal bearers sit. The stumps are adjusted, so the length is all level with each other.

If the building construction or extension is to be done on sloping sites, stumps are often used. In this case, the floor level is raised above natural ground level. Thereby, the minimum flood level requirement can be met or the views improved.

Timber Stumps

When you are looking for an environmentally friendly building option, you may opt for using timber pile foundations. They are affordable and durable. Moreover, they can be used on sloped sites with poor soil quality.

Other practical advantages include timber stumps being easily available and offering easy connections to floor bearers. In the same vein, you can simply adjust the height of timber stumps. Additionally, aside from dense hardwoods, treated pine is light and durable; as such, builders can easily handle it.

However, unlike concrete or galvanised steel, timber as a natural foundation material breaks down over time. Consequently, timber stumps require re-stumping every 20-70 years depending on the timber used, drainage, termite attacks, and soil conditions. Therefore you just may be wondering, whether the advantages of using concrete stumps out way the disadvantages?

Instead of using timber, you can use concrete. The following are a few advantages:

  • Concrete stumps give greater support and stability to the floors and walls of the building. The weight distribution of the floors is more even. Thus, the foundation develops minor wear and tear.
  • Concrete stumps are more durable. They rot and decay less easily and are more resistant to high humidity and temperature. This means that they are more likely to withstand poor weather conditions.
  • There is less maintenance needed with concrete stumps. Periodic checks are primarily for signs of cracks due to house movement and other general assessments.
  • Concrete stumps are generally non-combustible. Therefore, such foundations will not catch fire. This leads to better safety and security.

Galvanised Steel Stumps

Galvanised steel stumps are used when the underside of your building is more than 1.5 metres. Since steel stumps are adjustable on-site, you end up saving more time and effort during installation.

In addition, steel stumps do not have the vulnerabilities of wooden stumps. For instance, they are immune to termites. Likewise, they do not rot and will not warp over time.

When Should You Check Your Stumps?

You should not leave checking your stumps until when you want to renovate or sell your home. How else will you know if your house needs restumping?

The deterioration of stumps can impact negatively on the strength of your building. Your house can become unstable and unsafe. Unfortunately, concrete, timber, or steel stumps are susceptible to corrosion. As such, they cannot offer guarantees of preventing re-stumping.

Thus, you should check the stump of your house every few years regardless of the material used.

Signs A House Needs Restumping

Here are a few tell-tale signs your house may need restumping:

  • If the house was built before 1970
  • If there are cracks on the internal and external walls
  • If doors and windows are jamming in their frames
  • The presence of sloping floors
  • Presence of decay in foundations beneath the house
  • Damage to plumbing
  • Finally, you should consider restumping if you are making alterations and additions to your house. After all, you are adding a greater load on the supporting structure.

Restumping When Getting Your Home Renovated

Read on for tips on restumping:

  • First, assess what stumps need replacement or resetting. Do this by checking stumps for movement and deterioration. For example, inspect the subfloor frame for damaged or rotten bearer joists and wall plates. Perhaps, they need to be replaced.
  • Second, at the location where stump replacement is to occur, jack up the house slightly. This is to allow you to pack out such stumps that need replacement. For instance, you can set up your jacking equipment under the subfloor framing area.
  • Next, the stumps are hung from the bearers. The appropriate stump has to be used. For instance, the wire-fixed stump is ideal for use under walls. Likewise, for the bolted or threaded stump used under floors.
  • After that, level the house before you pour the concrete. Simply raise or lower the jack evenly to reduce cracking.
  • Now, you can pour the concrete. Perhaps, a concrete pump can be used. Pump the concrete into the holes around the stump and under it to form a support pad.
  • Finally, when the concrete is set, remove the supporting jacks and backfill the holes. Remember to tidy up.

Restumping With Steel Posts

With restumping, you are replacing the foundation supports of your building. As such, restumping can be really time-consuming.

How to use the Space-IT Pile Pad

The Space-IT Pile Pad increases efficiency and productivity. This is because you no longer need to support piles off the ground. Moreover, you no longer have to wait for the concrete to go off before the bearers come in.

When getting steel posts in the ground, you begin by capping the base of the steel post with a steel plate. This will enable it to sit correctly in the Space-IT Pile Pad. Thereafter, attach the steel post using steel self-tapping screws through the side of the Space-IT Pile Pad.

Benefits of using the Space-IT Pile Pad for steel posts

  • First, it reduces the time to put steel posts in the hole and get them ready for concrete.
  • Second, the stumps are accurate and meet local standards for concrete pad footings.
  • Generally, the move-out time for everyone living in the house is reduced.
  • Above all, you no longer have to support the pile off the ground. The Space-IT Pile Pad allows up to 100mm for capping off the bottom of the hole and sealing off the post. Ultimately, this makes for easy foundation building.

Steel Stumps Vs. Concrete Stumps For Building

Steel is widely considered to be the best choice for restumping. Indeed, it is more versatile than timber or concrete. In addition, galvanised steel, when correctly installed, can make steel stumps last for decades.

Furthermore, steel stumps take care of moisture runoff. Moreover, steel stumps can support steel beams, which makes them useful in renovations. In other words, you end up future-proofing your home for stump renovations.

Finally, galvanised steel stumps are lighter, easier to handle, and lasts much longer.

Professional Services On Stumps For Building

Even with a guide on steel stumps vs. concrete stumps for building, you may still need professional guidance on re-stumping. Perhaps, you need to replace red gum stumps in your home. There are professional home renovations and extension servicing companies that you can consult. Furthermore, upon undertaking a Building Inspection your building inspector will be able to inform you of a restumping option to suit your home.

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