Are you looking for the best way to construct a cellar for your next project?

Traditionally, cellars have been built using blockwork or concrete for decades. Because of this, and over time, they tend to leak and have earned themselves a reputation for being dark and damp spaces.

Constructing a cellar using traditional methods is also often considered a bit of a risk, with long periods spent on-site.

But what if I told you there was a guaranteed solution to these age-old problems?

As a subcontractor specialising exclusively in prefabricated steel, I’m going to tell you more about the differences between in situ and prefabricated steel cellars.

Constructing a cellar using in situ concrete

In situ may be the most obvious choice; after all, it’s been used by the construction industry for 80 – 100 years. However, just because it’s long-established (and relatively cheap), doesn’t mean it’s the best way to construct below-ground.

It can actually be the most challenging below-ground construction method, and it comes full of risk – not to mention the fact that you can be left with a cellar that has a low tolerance level, and may even become cracked and damp over the years (as cellars are known to do).

There’s also the issue of unskilled labour, as you’ll need operatives to enter the excavation to complete the works. And with the weather conditions Britain is notorious for, plus the logistics of completing the job and moving materials, let’s just say it’s not always the best choice.

Despite this, it can still be the best solution if you need a substructure to cover a large area (like a super cellar, for example).

Constructing a cellar using prefabricated steel

I’m now going to hazard a guess at what you’re thinking:

“So, Ross – what’s the alternative? Could it have something to do with prefabricated steel, by any chance?”

You’re damn straight.

Prefabricated steel is a much newer, more innovative method of below-ground construction. However, the main problem with it is that hardly anyone’s heard of it yet. Unfortunately, that doesn’t tend to inspire confidence.

But let me explain more:

Prefabricated steel substructures are made entirely out of steel, off-site in a factory environment under strict quality control – along with constant monitoring and controlling. So, what are the advantages?

For one thing, they won’t leak or crack. Think of it as being constructed much like the hull of a ship – by using steel plates which are then welded together. So, particularly if your cellar is going to be in a high water table area, you can be confident it won’t leak.

It can also last over 100 years in the ground, under the most acidic ground conditions. Not to mention, it can also be installed 70 – 80% faster than in situ! So, if time is a main driver for your project, prefabricated steel is a great option – as long as you can order at least 6 weeks ahead.

Finally, prefabricated steel cellars can also be built to very, very high tolerances (+-3mm), which in turn helps to lower long-term maintenance costs.

TIP: Want to know more about steel prefabrication? Read my recent blog: ‘What is Steel Prefabrication Below-Ground and How Does it Work?’.

Advice from a specialist subcontractor

If you’re confused about which option might be best for constructing the size and type of cellar you need, consider the speed and other benefits of prefabricated steel, compared to the risks of in situ concrete.

Think through all your options and address each and every risk of constructing below-ground level. General risks are part of all construction activities, but using old methods to construct watertight spaces still leaves questions hanging over it.

Understand what your priorities are, and how you want your cellar to perform over 10, 20 or even 30 years, before you take on the cheapest option.

Remember, prefabricated steel cellars are completely bespoke, so are usually a good fit if you’re looking for something that can not only be built economically, but to high tolerances and also resulting in a cellar that’s completely watertight.

It’s also good to bear in mind that for cellars, it’s often the case that prefabricated steel can be 70 – 80% quicker to install on-site compared to in situ concrete – meaning you can get a lot more use out of your cellar.


I hope you’ve enjoyed reading, and that this blog has managed to shed some light on how prefabricated steel compares to in situ concrete when deciding on the best method of below-ground construction for your cellar.

If you’d like to learn more about whether prefabricated steel might be a good option for your project, I’d urge you to get in touch with us to discuss your options further – we’re happy to listen, and offer a completely tailored service.

Alternatively, if you have any more general questions, just leave me a comment below – I’ll be happy to reply with something helpful!