Who repairs floor joists? The best trade to hire

In this article we will be looking at who repairs floor joists. As well as the reasons they may need repairing, or replacing

Floor joists are something found in every house with more than one floor. They provide a platform for floorboards to be laid on, and they are covered on the underside by the ceilings.

Because they are hidden, most people won’t give them a second though. However, if they become damaged and need replacing, or repairing, this can be a big job.

Because the timbers are hidden below floorboards and ceilings, working on them can be disruptive.

A carpenter is the best person to repair floor joists. This is a skilled job, and the floor joists are an integral part of the properties structure. Therefore, you want the work doing right.

In some cases, a general builder, or a handyman with experience in this type of work, may be able to help. However, A skilled carpenter is definitely the best option.

Common reasons to repair or replace a floor joist

who repairs floor joists
Me fixing some rotten joists in a property we renovated

There are several reasons you may need to repair or replace your floor joists. A few of the most common can be seen below:

  • Rotten joists. This is probably the most common
  • Damage caused by wood burrowing insects (woodworm).
  • Damage to joists caused by improper cutting. This can be holes and notches created to run services such as water electric and gas.

If any of these are affecting your floor joists you may start to notice sagging in the floor, or movement when walking over the damaged area.

When joists rot near the walls it is very common for the floor to have a noticeable bounce. This is usually an indication, that the ends of the joist are exposed to moisture and have started to rot.

The movement happens because the joist is no longer housed tightly into the wall. As it rots and deteriorates, it can move in the opening and may even completely break away.

If you have a problem with woodworm, you could potentially go years without noticing. The beetles lay larvae in the wood, and it remains there for up to 3 years eating the timber. If this isn’t fixed, it can spread and cause damage throughout joists, floorboards, and any other timber it spreads too.

Whatever the issue is, you should aim to fix damaged joists as soon as you notice them. Leaving them can lead to the problem worsening and this could be dangerous in the long term.

To avoid rot and insect infestation in the future you should consider treated floor joists

How much does it cost to repair floor joists?

The cost of replacing or repairing joists, will usually depend on the extent of the work. This will include the amount of time it takes which will be determined by the amount and complexity of the work. This will include things like:

  • How they access the joists. For example, will they need to remove floorboards or sections of ceiling?
  • How many joists are affected?
  • And will they be repairing joists or replacing entire joists.

Obviously, removing the end of one rotten joist and repairing with new timber, is a much smaller job then replacing several entire joists.

The latter will require a carpenter to remove large amounts of flooring. As well as sections of the ceiling below. There will also be more work involved fitting the new joists and this may be a two-man job.

Small repairs will be much less disruptive with small sections of floor and ceiling removed and less heavy work as the are working with smaller sections of joists.

A typical hourly rate for a carpenter, is approximately £25-£35 per hour. This means that a small job repairing joists could be a day’s work. So, in theory you could expect to pay £200 – £280 for labour + the cost of any materials. Materials would include things like new timber joists or I joists and fixings.

For a larger job replacing multiple joists, you could be looking at a couple of days and a two-man job. As a result, this could be considerably more. For this type of job, you should expect to pay between £800 – £1100 + the cost of materials.

Individual joists could set you back between £25 – £50+ each depending on width and length.

Get the best price for repairing your floor joists

As with any job where you hire a skilled trade, the best way to get a good price is shop around. Thanks to the internet you can easily do this online. Most good tradesmen will be on comparison sites and the added advantage is they are rated and reviewed on these sites.

This can be a great way to filter out any cowboys, or people who are not qualified for the job.

People on these sites also know they are competing for the work, so the prices tend to be discounted, to remain competitive. It is not uncommon to see 30% or more in discounts, on day rates for labour. To compare local carpentry quotes and see how much you could save Click here


A carpenter is the best person to deal with any work relating to repairing or replacing joists. They are a skilled trade, and this is a job that most qualified carpenters will have significant experience in.

Even if a joiners day rate is higher than a handyman or general builder. They can probably do the job faster (which will make it cheaper) and to a much higher standard.