How Many Tiles May You Need?
For a 5m x 3m utility room with 150 x 150mm tiles, our estimate suggests you may need around 706 tiles to cover the 15m² floor area, including an allowance for waste and cuts. Since this is a wet area, you'll likely need water-resistant adhesive and proper waterproofing behind the tiles to help prevent moisture damage. Choosing suitable materials for a utility room is important for long-lasting results. This guide walks you through the key considerations for tiling your utility room floor.
How to Measure Your Utility Room
Accurate measurements are the foundation of any successful tiling project. Measure the length and width of your utility room at the widest points, as most rooms are not perfectly rectangular. Work in metres for consistency with tile coverage calculations. For rooms with alcoves or recesses, break the space into rectangular sections and add them together. To check your room is square, use the 3-4-5 triangle method: measure 3 metres along one wall, 4 metres along the adjacent wall, and the diagonal between should be 5 metres. If the room is out of square, you may need to plan your tile layout to minimise awkward cuts at the edges.
Choosing 150 x 150mm Tiles for Your Utility Room
Smaller tiles like your chosen 150 x 150mm size are excellent for compact rooms and spaces with curves or awkward shapes, as they follow contours more easily. They also provide better grip underfoot due to the increased number of grout lines, making them a popular choice for shower trays and wet room floors. The trade-off is more grouting work and longer installation time. Always order a few extra tiles beyond the estimated amount in case of breakages during cutting or for future repairs.
Tile Layout Patterns
The two most common floor tile layouts are straight (grid) and diagonal (diamond). A straight layout is simpler to install and typically requires around 10% extra tiles for waste from cuts at the edges. A diagonal layout creates a more dynamic look but increases waste to approximately 15%, as more cuts are needed where tiles meet the walls at an angle. Brick bond (staggered) is another popular alternative that adds visual interest without the extra waste of a diagonal layout. With a larger floor area, you have the freedom to experiment with diagonal or herringbone patterns that can add real character to the space. Whichever pattern you choose, always dry-lay a few rows first to check the look before committing with adhesive.
Suggested Materials
Based on your 5m x 3m utility room (15m²), the estimated quantity is approximately 706 tiles, around 75kg of adhesive (roughly 4 x 20kg bags), and approximately 15kg of grout (roughly 3 x 5kg bags). For a utility room, use a flexible, waterproof adhesive such as BAL Rapid-Flex or Mapei Keraquick. Standard adhesive is not suitable for wet areas as it can break down with prolonged moisture exposure. Always buy slightly more than estimated to account for any wastage during mixing.
Installation Tips
Start by finding the centre of your utility room and snapping chalk lines to create a cross. Begin tiling from the centre outwards so that any cut tiles at the edges are symmetrical. Use tile spacers to maintain consistent grout joints and check your work regularly with a spirit level to ensure tiles are flat and even. Before tiling a utility room, apply a tanking membrane or liquid waterproofing primer to the floor and at least 150mm up the walls. This is essential to prevent water seeping into the subfloor and causing damage. Smaller tiles like these are often available on mesh-backed sheets, which can speed up installation significantly. If using individual tiles, a good pair of tile nippers will help with small cuts. Allow the adhesive to cure for at least 24 hours before grouting, and avoid walking on the tiles during this time.
Estimated Cost
Tile prices in the UK vary widely depending on material and finish. For your 15m² utility room, budget tiles typically cost between £10-20/m² (£150-300), mid-range options run £20-40/m² (£300-600), and premium tiles can be £40-80/m² (£600-1200). Adhesive costs around £15-25 per 20kg bag (£60-100 for your project), and grout is approximately £8-15 per 5kg bag (£24-45). If you need a wet tile cutter, hire is typically around £30 per day. In total, you might expect to spend between £264 and £1375 depending on your tile choice and whether you hire tools.