4 Factors That Will Determine Your Underpinning Costs
Underpinning a house is a necessary procedure if settling, or signs of settling, has been noticed. Without this comprehensive process, your house could dilapidate to a point where it is no longer safe to live in. Without a doubt, underpinning is quite an investment. The exact underpinning costs will be determined by a number of factors as explained below.
How many places need underpinning?
When houses need to be underpinned, it's usually in select areas only and not around the entire house. One of the factors, therefore, that determines the cost of the exercise is the extent of the damage. Is it in just one place (e.g. a corner), is it in two places, or is it in several places throughout the house? The higher the number of the affected places, the larger the repair costs, as all those locations will need to be dug out and underpinned.
Steel or concrete reinforcement?
Underpinning can be carried out using several materials. The most common are concrete and steel beams. Concrete is more common but steel is still used in some applications. Concrete tends to be cheaper than steel, although this will depend on the scale of the job. Special self-raising steel bars are sometimes used in underpinning jobs. These are even more expensive than standard beams as they can be adjusted to the needed height when levelling the house.
How big is the house?
In order to determine how much reinforcement is needed to underpin the house, contractors and engineers have to calculate the size of the house. Bigger houses bear more weight and therefore need more reinforcement. More reinforcement means more concrete or more steel, and hence higher underpinning costs.
What depth is needed to reach solid rock?
For an underpinning service to be effective, the reinforcement must link the subfloor to solid rock underground. This is the surest way to avoid settling from occurring again. The solid rock is used as an anchor point to prop your house up. This helps to get around most common settling problems such as shifting moisture levels in the soil or poorly-compacted sub-grade soils. If the solid rock is close to the ground, little excavation is required, and this lowers the underpinning costs. However, if the solid rock is far below the surface, more work is needed and costs go up.
Other factors that will also affect your underpinning costs include labour costs (depends on your locality), transport (depends on how far your house is from the contractor's base of operations), and availability of labour.
