What will need to be replaced this spring with regards to winter damage on your garden patio and decking

So winter is over and you are getting back out there. Nice warm spring day, with a lovely cup of tea and your decking is just not looking quite right. Or your patio slabs aren’t aligned like they should be.

Winter really does a number on your outdoor flooring. Constant freezing, getting moist and frost will creep into every crack over the winter and do damage.

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Wooden decking is the most impacted by this kind of damage. The boards get wet and expand, dry out and then contract. When it is really cold they freeze. This cycle occurs over and over every winter.

If you need to check the damage this winter will have done then check the ends of the boards first. This is where you will see splitting of the boards. The hairline cracks you will have gotten will over the winter. Every winter that is left should get progressively worse. You will have to get a solution for them and I can tell you it wont be leaving them to dry out. You will get water saturated and the entire board will just rot from the inside.

Check the gaps between the boards at a consistent distance. If the gaps are uneven or some of them have closed or opened the boards are shifting. If the framing is shifting, that means the loose fixings are causing the problem. If you can, check the joists. Wood does not like stagnant water on horizontal surfaces.

The wood composite decking is more resistant to damage but it is not immune. The boards can be frost resistant, but are the fixings? That’s what the problem usually is. Metal screws get loose over time due to it expanding and contracting at differential rates. If you hear creaking when walking on the deck, it means the fixings are loose and the boards are moving.

Patio Slabs and the Frost Problem

Frost damage on pavings is sneaky because you won’t always see it straight away.

What happens is this: The water freezes when it seeps into small gaps within the stone or concrete, expands and makes the crack it is in deeper. If this happens multiple times over the season, it will result in chunks of the surface breaking off. The corners are usually the first place to go, and are usually the first part to have calving, when surface flaking starts to happen.

Certify your slabs are smooth to the touch. Any elbow is frost damage and will get worse. Unfortunately, there is no adequate way to repair frost damage. Your only option for heavily frost damaged slabs is a replacement.

Inspect the bed where the slabs are joined. This is called the pointing and it is typically made of mortar or sand. Pointing is often washed out during the winter and frost. Liquid precipitation, snow, and frost thawing in the joints can take the pointing. Without the pointing, moisture can get trapped under the slabs creating subsidence, and vertical movement.

When slabs are at the perimeter, push down to test if they are secure. An elevated perimeter slab should not yield to vertical pressure. If it does, the underlying base is problematic and has either eroded away or not settled properly. To fix this, the slabs need to be removed, the base re-leveled and the slabs re-laid.

The Frame is Always Important

No matter if you are using decking or paving, the frame is very important during winter. The structure underneath is more important than the slab surface.

Decking frames, the joists, and bearers that support the boards, stay in contact with damp ground all winter. Even treated timber rots eventually. Use a screwdriver to prod the timber. It should feel solid, but if it goes in easily, that means there’s soft timber and more extensive work will be needed, not just the simple task of replacing a few boards.

The concrete pads or blocks that support the decking frame will all shift with frost heave. That is when the frozen ground expands and lifts everything that is sitting on top, then when it thaws, it unevenly settles back down. Your nice level deck from last summer? It is not level anymore, and you will feel it as you walk across it. There may be a slight dip or rise where there shouldn’t be one.

The sub-base underneath a patio does all the real work as well. If water gets in there and freezes, it can lift the whole patio, but when it thaws, it settles back down to a new position. That is why you can get sunken areas or slabs that rock underfoot.

Getting to repairs early can save more work in the future. But repairs that will be needed right away should be obvious and will be needed long before winter comes around again.

This is a priority: anything that lets more water in. Loose boards on the decking, cracks on the slab, anything that is missing pointing. Water causes the most damage, so waterproofing things is the priority.

So does the structural stuff. Things like rotten joists, sinking bases of the patio, loose fixings. These things get worse way too quickly, and they cost a lot more to fix.

Surface damage – scratches, scuff marks, faded colour – that’s more cosmetic. It looks rubbish, but is not actual damage. Sort out the structural stuff first, then worry about cosmetic damage like making it look nice.

And here’s the thing: some of this you can DIY, but some you probably shouldn’t. Re-pointing paving? It’s easy. Replacing rotten deck joists over uneven ground? Get someone else in who’s supposed to know what they’re doing. Otherwise, you’re just a false economy.