Floorboards

In this article, we will look at why MDF is not a suitable material for any type of sub floor. This includes small patch jobs and replacing individual boards. As well as jobs where larger areas are being covered.

The sub floor is a material that is fixed on top of the structural joists in a property. Its main function is to provide a flat, level, and stable surface for the finished floor to be laid on. In most properties the sub floor would be some form of timber floorboards, or an engineered sheet such as chipboard.

Other materials can be used, such as plywood and OSB. However, these are generally more expensive. In most older properties you will find standard timber floorboards. Whereas, in more modern and new build properties, chipboard flooring is more common.

All of the above options, provide a relatively strong level surface that distributes weight across the joists evenly.

Why MDF floorboards don’t exist

Unlike the materials we have mentioned previously, MDF isn’t a good option for this job. Below are 5 of the main reasons it shouldn’t be used in place of floorboards, or other engineered flooring sheets.

MDF does not have the load bearing capacity of other materials commonly used for floorboards. Solid wood takes its strength from the long fibres that run along the length of the board. These fibres result in high tensile strength and create a stable and durable surface.

Engineered woods that are commonly used in place of floorboards, also have good load bearing capacity. This is due to the way they are made, and the type of materials used to form the sheet. For example, plywood combines multiple layers of solid wood. Each layer runs at a right angle to the next. This cross lamination creates a strong, high load-bearing material.

Something more common like chipboard isn’t as strong as solid wood or plywood. However, it is still considerably stronger than MDF. This is due to larger particles of wood, combined with strong resin adhesives. It also benefits from interlocking t&g joints.

In comparison, MDF is much weaker under heavy loads. The material is essentially made from wood dust and adhesive. This does result in a versatile material that can be used for a wide variety of jobs. However, it also means it can’t support heavy loads without bending or breaking.

Flexibility

All floors will have some level of flexibility. This usually allows them to expand and contract slightly with changes to temperature and humidity.

MDF on the other hand, tends to be very flexible. This can result in bounce as foot traffic moves across it. As well as more pronounced bending and sagging over time.

Long term resilience

Due to its poor load bearing capacity, and its high flexibility, MDF is far less resilient. With increased foot fall and additional weight over time, it is likely to deteriorate and result in an uneven surface.

Also, as the material becomes weaker due to wear and tear it becomes far more likely that it will break.

Poor moisture resistance

One of the secondary functions of a sub floor, is it protects from moisture. The floorboards act as a barrier that stops moisture from reaching the finished flooring above.

This is a common complaint with cheaper flooring options like chipboard, as this material does absorb moisture and can swell. However, MDF is far worse in this regard. MDF is highly absorbent, and it can swell and become weaker when exposed to moisture. As a result it is more susceptible to damage and sagging.

No tongue and groove

Due to MDF being such a bad material for floorboards, there are no companies that make a specific flooring product with interlocking tongue and groove joints.

And why would they?

We have already established this is a very poor material choice for flooring, hence no one makes an MDF floorboard product.

The fact that MDF isn’t made with a tongue and groove joint just adds to its unsuitability. Due to this, it is more prone to movement. For example, because MDF is prone to sagging, swelling, and even breaking, the chance of an uneven surface is far more likely without interlocking joints.

Conclusion

Using MDF as a sub floor, or even to replace individual floorboards is generally a bad idea. It is not designed for this type of installation and can result in a whole host of problems.

There may be some unique circumstances where you could get away with using MDF, but these will be extremely rare.

For example, if you had a very small patch job in an area with no footfall, it might be acceptable, if it is all you have access too. However, in my opinion, this would be rare. In 99% of cases, choosing a more suitable material would be the correct choice.

There are many reasons you may need to replace floorboards. This could be due to:

• Damaged boards
• Uneven floorboards
• Damp under floorboards
• Squeaking floorboards

If you do end up replacing existing boards, there are several ways you can do this. For individual floorboards, you may simply decide to replace them with a like for like material. This would mean buying some new wooden floorboard.

Another common option is tongue and groove chipboard flooring. This is a cheaper alternative, which is also easy to fit and can usually be installed quicker, due to larger sheets (600 x 2400mm).

But can you replace floorboards with plywood? This is a common sheet material, and it is known for being a strong and high-quality product. But can it be used for flooring?

The simple answer is yes, you can replace floorboards with plywood. However, plywood tends to be quite expensive. Also, standard sheets do not have a tongue and groove to form interlocking boards. This is preferred, as t&g helps to form and maintain an even surface.

However, you can actually buy tongue and groove plywood flooring. This is far less common than chipboard and you will likely need to buy online. But it does exist, and many people prefer to use it over chipboard flooring.

One of the main negatives of t&g plywood flooring is price. For 22 x 600 x 2400mm tongue and groove plywood, you should expect to pay around £35 per sheet. Compare this with chipboard in the same dimensions, and you will pay nearer £20 per sheet. As you can see, this is nearly twice as expensive.

Using non t&g plywood for flooring

If you do decide to use plywood for your flooring, it is better to try and source tongue and groove boards. Whilst standard boards are strong, they can have issues due to butt joints. One of the main issues would be the result of moisture.

When any wood-based material has changes in moisture content, this can cause it to expand and contract. Plywood is no different in this regard.

As the sheet takes on moisture it will expand, and when the material dries it will contract. This is not unusual and the same would happen with standard floorboards, and definitely chipboard.

The main issues occur when the joints are not interlocking. This can cause gaps, steps between boards and an uneven surface. With that said, in many cases, this movement is minimal, and you probably won’t have any issues, even if your only using standard plywood. Some of this movement can also be mitigated with good fixings.

This will be less of an issue, for replacing small areas such as individual boards. In this case, a small amount of movement would not cause any issues.

Advantages of replacing floorboards with plywood  

Whether you are replacing a small area with plywood, or an entire floor, it does offer some benefits.

The main benefit is strength. Plywood is made by combining thin layers of wood. This wood is cut directly from the surface of timber logs with a type of lathe. The lathe has sharp blades which peel a continuous layer of wood veneer from the surface.

Following cutting and drying, these layers are applied with a type of adhesive resin. They are then layered on top of each other, with the grain of each veneer sheet running at a right angle. This cross laminated structure improves the sheets strength and stability.

Following this, the sheets are compressed at high temperatures to bond them together.

The end result is a material with high tensile, flexural and shear strength, which make this a very strong product for use in flooring.

It is also worth noting, that plywood has far better water-resistant qualities than a product like chipboard.

So as you can see, it is stronger and more moisture resistant than the most popular like for like alternative (chipboard). The main reason chipboard is more common, is price. It is very likely that tongue and groove plywood, would be more popular if it were as cheap as chipboard.

As you can see, plywood can be used to replace floorboards. However, it is less common and there are other materials that are used more frequently. This is mainly standard timber floorboards, or tongue and groove chipboard flooring. There are also other materials that can be used, such as OSB, which just like ply can be bought in standard sheets or tongue and groove.

The main considerations when you decide to use plywood or not, will be cost and quality. If you really want a strong and robust floor, it might be worth paying a little extra for ply. However, in most cases, basic chipboard flooring is often sufficient.

Ultimately, the material you choose will be based on a case-by-case basis.

As energy prices rise and the cost of heating our homes increases, it is understandable that people want to improve the energy efficiency in their homes.

One of the best ways to do this, is to ensure that your home is well insulated. The main areas to insulate are the external walls of your property and the roof.

According to energy advice portal TheGreenAge, 35%+ of heat is lost through a property’s walls. The roof accounts for a further 25%, and up to 10% is lost through the ground floor. The rest is lost through gaps around windows and doors. As well as the heat lost when people actually open these doors and windows.

Due to this, it makes a lot of sense to ensure the outer envelope of the property is well insulated. Obviously, the main areas people focus on, are the outer walls, and the roof. These two will have the biggest impact on maintaining the overall temperature in a property.

Another area people may add insulation is under floorboards. To do this, you can use loft insulation such as mineral wool, or PIR insulation sheets such as Celotex, in order to achieve an extra layer of insulation.

The main benefit of adding insulation below floorboards, is it will reduce heat loss from individual rooms and between floors. If this is combined with insulation in external walls, and stud walls, it can create an internal envelope, enabling you to keep individual rooms warm.

This can be particularly useful if you only want to heat certain areas of your home.

Also, as we already mentioned previously, up to 10% of heat can be lost through the ground floor. Therefore, it can be quite beneficial to insulate this area where possible.

Insulating the ground floor

In order to reduce the 10% of heat loss that can leave through the ground floor of your property. Adding insulation can be a good solution.

However, the way you do this, will depend on the type of floor you are trying to insulate. The main scenarios include:

Solid concrete floors

There are only two ways to do this. Firstly you can dig out the floor. This will be a huge amount of work and you will need to add a new DPM, rigid insulation, and then pour more concrete.

The second option is to lay insulation above the existing floor. Obviously, this comes with another set of problems, as it will raise the floor level. This will require a lot of adjustments, to things like sockets, skirting boards, radiators, etc.

Both of these scenarios are extremely disruptive. Which means it is usually not worth it for the benefit you would achieve.

Suspended timber floor with a crawl space

In this scenario, the void below the suspended floor can result in considerable heat loss. As a result, insulating can be a very good solution.

The least disruptive way to insulate the floor, would be via the crawl space. This is not the easiest of jobs, but if you can access the void below the floor, you can install insulation from underneath.

You may choose to add some netting below to avoid the insulation falling out.

If you can’t access the crawl space, the only way to insulate this area would be to remove floorboards. Again, this is quite disruptive, as you will need to remove flooring and any furniture above the floor.

Timber floor with a cellar or basement below

If you have a cellar or a basement, this is often the easiest way to insulate under the floorboards of your ground floor.

Access is much easier than a crawl space, and the joists are often exposed from below. If this is the case, you can easily add insulation from the basement.  

If you have a ceiling in the basement, you may need to remove it, add insulation, and re-install the ceiling.

Adding loft insulation under floorboards in other areas

You can also add loft insulation under floorboards in the other areas of your house. As we mentioned previously, it will provide extra insulation between floors. However, it can be quite disruptive.

To add insulation under floorboards, you will need to access the area. This will mean removing furniture and flooring, in order to lift the floor boards. Obviously, this is not a small job. With that said, you only need to do it once and the benefit will last for years.

There are definitely more important areas that need insulation. Therefore, if you don’t have sufficient insulation in your external walls or roof, these could be a better area to focus on.

With that said, if you are simply trying to add another layer of insulation, it is completely acceptable to add loft insulation under floorboards in any area of your home.

Conclusion

You can definitely use loft insulation under floorboards. It will provide another layer of insulation between rooms in your property. It can be very effective, especially combined with insulated stud walls and external walls.

The main issue with adding insulation below floorboards is the disruption caused installing it.

In order to access the area, you will often need to move furniture and flooring above. Following this you will need to physically remove floorboards. If this is something you are comfortable with, them by all means do it.

If you have a broken floorboard under your carpet, it will need repairing or replacing. To do this, you will need to pull the carpet back, in order to access the broken floorboard. Then you can identify the issue and determine the appropriate solution.

In this article, we will look at 3 different scenarios. We will explain how to fix floorboards under carpet, that are broken, damaged, or loose. Explaining the different techniques that can be used to fix them.

Whatever the problem is, it is best to identify and resolve the issue early. This will avoid any accidents and potential damage to your flooring. It will also help you to identify any more serious problems, that could become worse over time if not treated early.

How to remove carpet to access floorboards

If you have never removed any carpet before, it can be quite daunting to simply pull it up. However, it really isn’t that difficult. In most cases, the carpet will be held in place around the perimeter of the room, with carpet grippers.

Carpet grippers are small strips of plywood, with angled hooks that hold the carpet in place. Pulling the carpet from the grippers is relatively easy, and laying the carpet back down once you are finished, is also an easy job. You can simply lay the carpet back to the grippers and push the edge of the carpet back in. This can be done with a blunt tool such as a bolster chisel.

After removing your carpet to expose the problem floorboard, you will be able to get a clearer idea of the problem. Most commonly this will be one of three things.

1. The board is not sat on a joist
2. It is not fixed correctly
3. Or it is visibly damaged

How to fix a floorboard not sat on a joist

If the end of a floorboard is not sat on a joist, this means there is no support under it. This will cause the board to flex when it is stood on, and in the worst-case scenario it will break.

There are two main reasons this happens:

1. The board was fitted badly to the joists. This could be a board that only just hits a joist, but over time it has moved and slipped off. This can often be the result of damage to the end of the floorboard, which can be caused by wear and tear, over time.
   
   
2. The board has been cut and not supported afterwards. This usually happens when a tradesperson accesses below the floorboards by cutting boards, then fails to add support when it is replaced.

In either of these scenarios, you will need to add a support to carry the board. For option number 1, this can be done quite easily, by screwing a piece of wood to the existing joist.

In the second scenario, you may not have a joist close by. If this is the case, you will need to install a piece of timber below the end of the floorboard.

To do this, cut a piece of wood, that is at least twice as wide as a floorboard. Take this piece of timber and place it under the floorboard, so it under-laps the board either side of the hole. Next, screw through the floorboards either side into the timber below. This will hold the wood in place, providing a bridge support, for the end of your floorboard to sit on.

What to do if a floorboard is not fixed correctly

This is the simplest solution. In this case, the board is not broken, and it is sat on a joist. However, for whatever reason, it has not been fixed in place. This can feel like a broken floorboard when it is walked on, due to movement.

Assuming the floorboard is sat on a joist, and it isn’t damaged, you can simply screw it in place, and this should solve the issue.

What if the floorboard is definitely broken?

If the floorboard is visibly broken, it will need replacing. However, before you replace the board, you should try to determine why it broke in the first place.

Often, a defect in the wood can cause it to crack and break over time. This is not unusual, so assuming there are none of the previous issues, and the floorboard is sat securely on a joist, it can simply be replaced.

When replacing the board, you will need to determine the correct size to purchase a replacement. One thing to consider, is many old floorboards use imperial measurements. Whereas modern boards are usually measured in metric.

This can cause a slight discrepancy in sizes. With that said, it usually isn’t a massive difference (maybe a couple of millimetres). Also, you can source old floorboards if you really want an exact fit. Finally, things like chipboard or even plywood could be considered for minor repairs.

The only time you wouldn’t replace the floorboards straight away, is if there are signs of an underlying issue. This could be something like rotten floorboards, or a visible sign of woodworm. Both of these are serious issues, and you will need to treat the root cause, so it doesn’t spread.

For rotten floorboards, this is more common near walls and is a sign of penetrating damp. You will need to find the cause of this damp and rectify it, before replacing any wood. You should also check joists and remove them or treat them where appropriate.

If you think the problem is woodworm, you can learn more about treating woodworm in floorboards by clicking here.

Conclusion

In most cases, its easy to fix broken floorboards under carpet. Usually, after a quick inspection, they will either require securing properly, or they will need minor repairs or replacement. However, there are cases when a more serious underlying issue can be present.

If there are clear signs of damp, rot, or even wood burrowing insects, you will need to completely fix the issue before you replace any floorboards.

Chipboard flooring is a very common type of floorboard in modern properties. This is mainly due to its low cost and ease of fitting, compared with traditional timber floorboards. However, chipboard is lower quality compared to wood floorboards, which often means they may need replacing sooner.

This can be due to wear and tear, as well as issues with moisture causing the boards to swell and deteriorate.

The cost of replacing chipboard flooring, will depend on whether you hire a professional, or do the work yourself.

If you do the work yourself, your only expense will be the boards, the screws, and some wood glue. Prices will vary from one supplier to another, so you should shop around at larger DIY chains, as well as local builders’ merchants.

On average you will be paying around £15/m2.

Based on data collected by LABC (Local Authority Building Control). The average UK house size for homes built between 1930 and 2018, was 73.6 m2. This doesn’t include hallways, landings, or stairwells.

Therefore, if you were replacing chipboard flooring for an entire house, your cost for materials alone would be approximately £1,104.00.

This price could be lower if you shop around. £15 is a rough average per meter square. However, the lowest costs we found locally were:

• £10.83 m2 for 18mm chipboard flooring
• £13.33 m2 for 22mm chipboard flooring.

The full cost at these prices, would be £797.09 for 18mm chipboard, and £981.09 for 22mm. So as you can see, shopping around will make a big difference.

Also, don’t forget, you may need to add extra if you intend to board hallways and landings.

Cost of a professional replacing chipboard flooring

When you have a professional fit your chipboard flooring, you will have the cost of labour on top. This would usually be around 4 days’ work for the entire house and would include removing existing flooring and fitting new flooring.

The average day rate for this type of work, would generally be around £250. Therefore, labour would be somewhere in the region of £1000 providing the work is straight forward.

The work may be quoted on a day rate, or alternatively, it could be quoted as an entire job.

Based on average house size and the expected cost for labour, you can expect the labour rate per square meter to be around £13.59.

All in all, if we round everything up, a reasonable price would be somewhere around £28.59 m2, or just over £2100 for an average size house (minus hallways and landings).

However, it is important to point out, that these estimates are based purely on numbers and maths. This does not consider any issues that may be encountered. Or any unique circumstances that may be present.

It also assumes an average sized house. If the house is larger the cost will obviously be higher. Although, the cost per m2, should be a reasonably accurate guide.

If the job is for an individual room, such as a living room or a bedroom, you should expect to pay between £500-£600 for materials and labour.

Some other areas may be priced differently, such as lofts. This is due to several reasons, including:

• Access
• Working height (under eves etc)
• Insulation
• Additional support

Any of the above could add extra expense to the work being carried out.

Finally, removing chipboard flooring can be a headache. If it lifting the chipboard is particularly awkward, this could require more time and expense.

Ways to save money when replacing chipboard flooring

As we have already mentioned, you should definitely shop around for materials. Also, you can opt for 18mm boards as opposed to 22mm. This could be a good idea in areas that are just being used for storage, such as a loft for example.

Looking back to our local quote, the difference between 18 and 22mm was around 19% cheaper for the thinner board.

Another way to save money, is to shop around for quotes. You can even mention that you’re considering other offers when someone comes to quote on the job.

An even better way to get more competitive quotes, is taking the job online. There are several trade comparison sites that can often get you a really good price on this type of work.

There are several advantages to these types of website. The main benefits can be seen below:

• All the contractors are verified by the comparison site. This protects you from rogue traders and cowboys.
  
  
• Not only are they verified by the website, but they are also reviewed by customers. This means you can learn about their previous work and read what past customers had to say.
  
  
• Finally, it is a competitive marketplace. This means the companies quoting for jobs are competing on price, and they know it. Because of this, prices are often very competitive.  

We have seen savings as big as 40% off labour costs. This could be the difference between paying £250/day and £150/day.

Obviously, we can’t guarantee the discounts will be that good. However, it costs you nothing to enquire and often a rough quote can be given online.

To compare local quotes and see how much you could save Click here

Conclusion

Hopefully this has given you an idea of how much replacing chipboard flooring is likely to cost. The numbers here are estimates, and they should be used as a guide.

Basically, if quotes are coming in much higher, you can ask for a breakdown of the costs, to see what you are being charged for.

Alternatively, if the quotes come in lower, you know your getting a pretty good deal.

Either way, the best way of lowering the cost is to simply shop around. This includes materials and labour. If you can get discounts on both, this can drastically reduce the overall cost you pay.

Boarding out your loft is a great way to add extra storage to your home. For most people, this is an area that is not utilized, and is essentially wasted space.

However, boarding out your loft is relatively easy and can add a large amount of usable storage to your home.

Every loft is going to be different, so the amount of space and the layout will vary. However, if the area is just being used for storage, then the process will be very similar.

In most lofts, you will have trusses and supports running through the space. If this was being converted into a usable room, there would need to be adjustments made. For example, you would need to remove certain timber supports. These would need replacing with new forms of support, to open up the floor space, whilst ensuring the roof is still safe.

However, for storage purposes, this is not necessary, and you can simply fit the flooring around these timber supports.

Most common boards used in a loft

The most common floorboards used in lofts, are tongue and groove chipboard flooring. Although other options are available, such as OSB (orient strand board) and also plywood. Both of these can be purchased with tongue and groove, meaning they can be fitted identically to chipboard flooring.

However, chipboard is usually the cheapest option, and it is also more readily available.

Chipboard flooring comes in two main sizes, the largest is 2400 x 600mm. You can also buy smaller boards at 1200 x 320mm.

Larger boards are preferred. However, they are sometimes hard to get into some lofts. Smaller boards are much easier to fit through a smaller hatch into the loft space.

Chipboard also comes in two main thicknesses. These are 18mm and 22mm. For this type of job, 18mm is completely acceptable and will give more than enough support.

Finally, you have the choice between standard boards and moisture resistant boards. This is entirely up to you. Moisture boards will be more expensive, but they will also hold up better if you do have a roof leak onto the flooring.

Fitting methods and insulation

When it comes to fitting your boards, the first thing you want to do is check the joist spacing. In most cases the joists will be fitted at either 400mm or 600mm centres.

Sometimes, you may also find joist at 450mm, and occasionally, in older properties, there may be different spacing.

In the vast majority of cases they will be 400 or 600mm. Of these two, 400mm is the most common. The advantage of standard spacing, is it will allow you to fit 1200 or 2400mm boards without cutting. This is because a whole board should land halfway on a joist.

In this scenario, the only time you will need to cut is when you reach a wall.

Boards should run perpendicular to the joists, and this will add strength to the flooring. Also, you should stagger the boards. For example, your first row of boards would start from the left of your loft, and your second row would start from the right. This will ensure that all the joints are staggered. Again this will strengthen the floor.

If you can see the joists and they have insulation in the middle, you can simply board straight onto the joists. To fit your boards, use 30-40mm wood screws. This will give a secure fixing and ensure that you don’t suffer with squeaky boards. It will also make the chipboard easier to lift at a later date

You can also glue the tongue and groove joint, with a standard wood glue, for a solid fixing between the floorboards.

Solutions for thick insulation

For a loft that has thick insulation that is much deeper than the joists, you may need to raise the boards up above the insulation. This can be done with additional timbers, or you can use a solution such as loft legs, to raise your floor above the insulation.

Loft legs are basically small plastic legs, they form a support to raise your floorboards above the insulation. This will require a little more time and you will need to measure and space them out properly. However, they do offer an affordable solution for raising your lofts floor level.

You can see some instructional videos on there website here. The process is very simple, and you just screw the legs in place and then fit your boards on top.

This type of solution is strong enough to walk on and can support around 25kg per square meter. Therefore, if you are just using the loft for basic storage, it is a fairly decent option, that will allow you to not compromise on insulation.

If you do need more support, whilst still covering the additional insulation, then you will need to use timber to raise the floor level.

This can be done with 4×2, running perpendicular to the existing joists. By doing this, it will also allow you to run your two layers of insulation in two different directions.

This process is more time consuming and slightly more expensive. However it will produce a stronger floor. It will also mean adding additional support between the floor and roof is easier. This may be something to consider, if you ever intend to use the room for anything other than storage.

Conclusion

Essentially you have 3 potential ways of fitting boards in your loft:

1. Attaching straight to joists
2. Loft legs
3. Adding additional timber to raise the floor level.

Obviously, the first option is the easiest. Also, according to energy advice portal The Green Age, the heat loss difference between 100mm and 270mm of loft insulation is only around £13/. So it’s not massive.

With that said if you already have insulation. Or if you do want to add more, then loft legs are definitely a cost effective and easy solution to raise your floor above the insulation.

Timber is more expensive and more time consuming. However, it will add more strength and might be a better solution if you need more solid support.