How to build a bath frame

Tim
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Project Overview

If you are installing a new bath, you will need to support it with a timber frame. We’ll teach you how to build the frame to size and install it properly in your bathroom. You will also see how to reinforce the frame and compensate for an uneven floor.
Continue to Step-by-step instructions.
This D.I.Y. Advice is part of a series How To Install a Bath
Time Required

Done in a Day

Done in a Day

You'll need to set aside a day to comfortably complete this project

 
Weigh down bath with cement bags
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00:13
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Quick Tip

If you need to weigh a bath down, the easy thing to do is to fill it with water. But when your bath hasn’t been plumbed yet, use a few heavy bags of sand or cement to do the job instead.

Step by Step Instructions

1 Mark a line on the wall for the top of the bath frame
2 Install noggins between the wall joists to support the bath frame
3 Measure and cut the sides of the bath frame
4 Mark the positions of the vertical studs for your bath frame
5 Assemble the sides of the bath frame
6 Install the sides of the bath frame
7 Build the ends of the bath frame
8 Install the ends of the bath frame
  • Step 1. Mark a line on the wall for the top of the bath frame

    Measure the height of your bath. Add another 80mm or so and mark that level on your wall studs. This is the mark for the top of the frame. The extra 80mm allows for differences in floor height. In this case our bath is 370mm so we’ve marked our line at 450mm.
  • Step 2. Install noggins between the wall joists to support the bath frame

    Measure the gaps between each of the wall joists at the height of your line. Then use your circular saw to cut a timber noggin to size for each gap. Now nail the noggins into the gaps with your nail gun. The noggins give the bath frame extra support and hold external linings. 
  • Step 3. Measure and cut the sides of the bath frame

    Position the bath with one end sitting 70mm out from the wall to allow for the frame. Then measure from the wall to the far end of the bath and add another 70mm. Take this measurement and cut four lengths of timber for the top and bottom sides (plates) of the bath frame. 
  • Step 4. Mark the positions of the vertical studs for your bath frame

    Mark where the vertical studs will go on the top and bottom plates by tracing around an offcut of framing timber with a pencil. Put a stud at each end and space the others evenly along the frame every 600mm. Spacing them like this will make it easier later when you want to cover the frame.

  • Step 5. Assemble the sides of the bath frame

    Measure and cut eight vertical studs, all 95mm less than the height you want for your frame. The studs are 95mm shorter than the height of the frame to allow for the thickness of the top and bottom plates. We add 5mm to allow for any variations in the height of the floor. Nail the studs into place between your top and bottom plates to create the two sides of your frame.

  • Step 6. Install the sides of the bath frame

    Put one side of the frame in position against the wall. Then line the other side up so it is parallel. In this case, we’ve separated the two sides by 850mm, which is the width of the bath, minus 30mm. This gives us a 15mm ledge on each side of the frame for the bath to rest on. Once you’re happy with the position of the two sides, nail them into place.
  • Step 7. Build the ends of the bath frame

    Straighten the outside edge of the frame with a spirit level and measure the distance between the two sides. This gives you the width of your end pieces for the frame. Use this measurement to cut top and bottom plates for both ends. Then cut three vertical studs for each end, using the same length you used for the previous studs. To assemble each end, nail three studs between a top and bottom plate.

  • Step 8. Install the ends of the bath frame

    Use your nail gun to secure each end in place. In our case, one of our ends is unsupported by a wall. So as we nail it, we use our spirit level to check that its vertical edges are right. To finish, place the bath inside the frame to make sure it supports all four edges properly.

Please make sure you use all equipment appropriately and safely when following the advice in these D.I.Y. videos. You need to be familiar with how to use equipment safely and follow the instructions which came with the equipment. If you are unsure, you may feel it is safest to consult an expert, such as the manufacturer or an expert Bunnings team member.

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