Can I use something other than concrete?
Absolutely - you don't have to use concrete for your heat pump base. There are several lighter alternatives that work just as well and are often easier to handle.
Lightweight composite slabs are popular options. They're made from materials like reinforced polystyrene with a cement coating, so they look like regular paving slabs but weigh much less. You can easily lift and position them yourself, plus they're simple to drill if you need to secure the unit.
Plastic or rubber pads are another good choice, especially if noise is a concern. They absorb vibrations better than concrete, which can help reduce the humming sound. You'll want to put them on a well-prepared gravel base for stability.
The key things are making sure whatever you choose is perfectly level and provides proper drainage. An unstable or waterlogged base will cause problems down the line. Most heat pump installers are familiar with these alternatives, so don't worry about straying from traditional concrete.
Interested in more details?
Alternatives to Concrete for Heat Pump Mounting Pads
If you're installing a heat pump and wondering whether you really need to pour a concrete pad, you're not alone. Many homeowners assume concrete is the only option, but there are actually several alternatives that can be easier to install, lighter to handle, and sometimes even better for reducing noise.
What Can You Use Instead of Concrete?
Lightweight Composite Slabs
These are probably your best bet for a DIY installation. Made from an encapsulated polystyrene core with a textured cement coating, they look like heavy-duty paving slabs but weigh much less. You can actually lift them yourself rather than needing several people or machinery. They're also easy to drill if you need to secure your heat pump with bolts.
Expect to pay around £40-80 per slab depending on size. For a typical air source heat pump, you'll likely need 2-4 slabs.
ArmorPad and Similar Products
These purpose-made HVAC pads are designed specifically for heat pumps and air conditioning units. They're lightweight, durable, and provide excellent stability. The main advantage is they come ready to use - no mixing, no waiting for concrete to cure.
Prices typically range from £60-150 depending on the size you need.
Rubber or Plastic Composite Pads
These work well when placed on a properly prepared gravel base. They're excellent for vibration dampening, which can significantly reduce the noise your heat pump makes. This is particularly useful if your neighbours are close by or if the unit will be near bedroom windows.
UK Regulations and Considerations
The good news is that UK building regulations don't specify you must use concrete. What matters is that your heat pump is stable, level, and properly supported. Your local authority or MCS-certified installer will be more concerned with noise levels, planning permission requirements, and proper installation than the specific material you use for the base.
If you're claiming the government's Boiler Upgrade Scheme grant (worth up to £7,500 for air source heat pumps), your MCS installer will advise on appropriate mounting options that meet the scheme's requirements.
Pros and Cons of Concrete Alternatives
Advantages
- Much easier to handle and position - no heavy lifting equipment needed
- Faster installation - no waiting for concrete to cure
- Better vibration dampening with rubber options
- Can be repositioned if needed
- Often work out cheaper than hiring concrete trucks and labour
Disadvantages
- May not be suitable for very heavy commercial units
- Some options require more careful ground preparation
- Might not last quite as long as properly installed concrete
Common Installation Mistakes
The biggest error people make is not preparing the ground properly. Whatever material you choose, you need a level, well-compacted base. Many installations fail because the pad wasn't level to begin with, causing the heat pump to vibrate excessively.
Poor drainage is another common problem. Make sure water can drain away from your chosen pad material - standing water can cause long-term issues regardless of what you're using as a base.
Don't forget to check the manufacturer's specifications for your specific heat pump model. Some warranties might require certain types of mounting bases.
Making Your Choice
For most domestic installations, lightweight composite slabs offer the best balance of cost, ease of installation, and performance. They're particularly good if you're doing the work yourself or have limited access to the installation site.
If noise is a particular concern, consider rubber composite pads. They cost a bit more but can make a noticeable difference to operational noise levels.
Remember to factor in ground preparation costs whichever option you choose - you'll still need proper excavation, hardcore, and sand blinding for the best results.