Knocking Through a Wall: Guide & Tips
Turn two rooms into one, or a small space into a large one: knocking through a wall lets you design your home exactly the way you want it. Ready to grab a sledgehammer and go for it? Not so fast! We've got tips for both load-bearing and non-load-bearing walls. We'll show you what to look out for, what costs to expect, and which tools will help you get your DIY wall opening project done right.
Checklist for Knocking Through a Wall: What you should check first
- Written permission, if you are renting
- Building plans for your home
- A structural survey
- Planning permission, if required
You can find the building plans at your local planning authority. These will show you which walls are load-bearing, where pipes and cables run, etc. Planning permission is required if:
- the opening affects a load-bearing wall,
- it is an external wall,
- the building is a listed building.
Our tip: When tackling a major DIY project like knocking through a wall, always play it safe! Be sure to check with your local planning authority and a structural engineer. This will help you avoid any nasty surprises, as well as potential deconstruction orders or heavy fines.
Load-bearing vs. non-load-bearing walls – how to tell the difference
Only a structural engineer can definitively tell you which type of wall you're dealing with, but there are some rules of thumb. The following are usually considered load-bearing walls:
- Exterior walls
- Walls with a thickness of 17.5 cm or more
- Masonry walls with a thickness of 11.5 cm or more (in buildings from 1990 onwards)
It gets more complicated with older buildings, so getting expert advice is especially important here.
You can often identify non-load-bearing walls by their sound: if it sounds hollow when you knock, it's likely a stud partition wall, which you can generally remove – as long as there are no pipes or wires in the way!
What tools do you need for a wall breakthrough?
To knock through a wall, you'll need to bring out the heavy-duty tools. The most important power tools and hand tools are:
- Rotary hammer: A powerful tool for getting through solid masonry
- Sledgehammer: When you need brute force – perfect for making the first hole
- Angle grinder (with a diamond cutting disc): For cutting into plasterboard or lightweight blocks
- Hammer & chisel: The experts for fine-tuning and lighter materials
- Core drill: For precise, circular openings for pipes
Tool Tip: For thin walls made of plasterboard or similar materials, your hammer drill should have an impact energy of 10 to 20 joules. For thicker walls, 20 to 50 joules are required.
Making an Opening in a Non-Load-Bearing Wall: Guide & Tips
Creating an opening in a load-bearing wall is a job for the professionals. For a non-load-bearing wall, here's how you do it:
- Get your tools ready and put on your protective gear (ear protection, safety goggles, protective clothing, work gloves, safety boots).
- Cover the adjacent rooms with dust sheets – including floors, walls and furniture.
- Mark out the opening – especially if it's for a door or window. It's best to be a little generous with your measurements.
- Use a sledgehammer or rotary hammer to first chisel off the plaster, then switch to the drill function. Drill a hole every 5–10 cm along the line of the opening.
- Remove the rubble, install the door or window, and plaster the opening – for example, with plasterboard or plaster. Fill any gaps with expanding foam or cement.
Knocking Through a Wall: How to Calculate the Costs
How much your wall opening will cost depends on many factors. There are various ways to calculate this, which mainly depend on whether you hire professionals or do the work yourself. On top of this, you have the labour costs for tradespeople, as well as call-out fees, costs for rerouting pipes or wires, etc. Get a quote from a local professional and compare the offers. When you do, don't just look at the final price, but pay close attention to the scope of services included!
