Episode: Seven
Date: 19th April 2008
Presenter:  Phil Dudman
Story Title: Mitre10 Project Planners- Build a Cubby House

Step One: Mark The Site
Try to pick a site that is slightly in a shaded position so it doesn’t become to hot for the children in the summer, and with enough ground around it to extend their play outdoors. Mark an area measuring 1800mm square be driving four corner pegs into the ground and joining them with builders sting line. Lines one and two should be equal length, lines 3 and 4 should be equal length. Then measure the diagonally opposite corners, lines 5 and 6. Adjust the corner pegs if necessary until both these lines measure the same, but make certain that the measurement along lines 1, 2, 3 and 4 remain at exactly 1800mm to ensure the site is both parallel.

Step Two: Build Floor Frame
The foundation is the most critical stage of construction. Any errors here will affect all later work, so take your time and double check all measurements and setting out.
Dig corner stump holes 400mm deep x 300mm square. Dig them so that when the stumps are centered in them, their outside edges are flush with the string line. Place a timber sole plate in the bottom of each hole and stand a stump on it. Or use a 50mm layer of concrete instead of the timber sole plate. Measure and mark 70mm up from the ground level on the outside stump located at the highest point of ground level. Transfer this mark to all other stumps by using a 2100mm length of each straight timber and spirit level. Mark all four sides of each post with a carpenters square, remove the posts and cut to the marked lengths. Replace in their holes when cut to size.

Now cut two 100 x 100mm bearers to 1800mm long. Place them on top of the stumps, making sure the outside surface of each stump is flush with the end of the barer and skew nail the bearer to each stump with two 75mm galvanized nails.
Cut five 100 x 50mm joists to 1800mm long. Skew nail a joist to each end of the bearers with two 75mm galvanized nails per fixing point. Set out the three other joists 387mm apart on the bearers and fix them to it in the same way. Now check that the floor frame is square by measuring diagonally from corner to corner as in Step One. The frame can be pushed and shoved at this stage until both diagonal measurements are the same. Finally, replace the soil in the stump holes and tamp down hard.
Complete the frame by cutting the sheet flooring in half so you have two 900mm x 1800mm long pieces. Lay one sheet on the joists with the plastic tongue in the centre and fix to each joist with galvanized 60mm flat head nails at 200mm spacings. Remove the plastic tongue from the remaining piece, lay it on the frame and push it into the tongue of the sheet already fixed. Nail it to the joists as before.

Step Three: Make Wall Frames
Start by cutting twenty 70 x 35mm studs, five each wall, to 1430mm long. By the time top and bottom plates are added, the walls will be 1500mm high.
Next, cut the top and bottom plates for the front and rear walls to 1800mm long and the end plates, which are located between them, to 1660mm long. Lay the plates in pairs on the floor at the wall positions. Mark the stud spacings on each pair and code mark them for each wall. Now, remove the plates in pairs to make the walls, the front wall first. Lay the plates the length of a stud apart. Place five studs in their approximate positions between the plates as marked. Nail the plates to each stud with two 75mm galvanized nails. Stand the wall frame up and temporarily brace it in position. Nail the bottom plate at each corner with a 75mm galvanized nail and into the flooring at each floor joist.
Make a side wall frame in the same way and fix it in position as before. Then connect the walls by nailing the corner studs together 150mm from the bottom and top and one in the centre. The rear wall and remaining side wall frames are made, positioned and fixed to the floor and each other using the same procedure. Finally check all corners are plumb and temporarily brace each wall from the inside to hold the structure plumb.

Step Four: Make Roof Frames
Cut six main rafters to 1155mm long which includes a 100mm overhang of the walls. Rafter ends are cut at an angle to the pitch of the roof. To ensure the correct angle, make a template first from timber scrap as shown. Then set a sliding bevel to the angle and mark both ends of each rafter. At the same time, mark the foot cut to the same angle. To make the frame, lay one pair of the rafters on a flat level surface with the tops pressed firmly together and the foot cuts 1800mm apart. Nail the rafters together at the top with a gang nail plate. Turn the rafters over, check the foot cuts are 1800mm apart, and fix a gang nail plate on this side, too. Make the two other frames in the same way. Lastly, cut four 70 x 35 x 847mm pieces of pine and nail two to each of the front and rear wall top plates for fixing the rafter frames and wall lining.

Step Five: Raise the Roof
You’ll need an extra pair of hands to help you here – one to hold the rafter frame in position while the other nails it. Place one of the end frames in position and skew nail to the plate on each side with one 75mm nail through the rafter foot cut into the plate and one directly into the plate block. Do the same at the other end. Then fix middle frame by skew nailing through the foot cut with one nail each side. Now cut four 70 x 35 mm roof battens to 1800mm long. Nail the top battens 100mm down from the ridge point on each side with two 75mm nails at each fixing point and the bottom battens 50mm up from the bottom of the rafters. The roofing overhangs the bottom of the battens by 100mm. Fix it to the battens with roofing nails through the top of the corrugations and every third corrugation. Finish by nailing on the ridge capping.

Step 6: Complete Structure
With wall frames fixed and roof up, make the door and window frames from 90 x 19mm treated pine. Measure the openings, then cut and make the frames to suit. When installing, make sure they will be in line with the outer surface of the wall lining and nail to the studs with 50mm galvanized nails.

Step 7: Add Wall Lining
There’s an array of different exterior wall lining materials on the market today, including weatherboard, cement sheet, Weathertex building boards, exterior grade plywood, and others. The choice is yours and your Mitre 10 store can help you choose and provide the necessary information and manufactures fixing instructions. Whichever you pick, the lining should extend 20mm below the bottom of the floor joists. When the wall lining is on, cut the 90 x 19mm treated pine fascia boards. Cut them to the same length as the rafters with the same end cuts but not the foot cuts. Fit them to the gable ends over the wall liningw the top of the fascia board in line with the top of the roofing corrugations. Then nail a 70 x 19mm treated pine capping to the top of the fascia. Finish by fixing 42 x 19mm treated pine architrave over the outside of the door frame and the lining boards for a neat and water tight finish.

Step 8: The Final Touches
Adding the door and window means you’re nearly there. Measure the door frame opening, then cut the exterior grade plywood 4mm smaller than the opening. Fot the “T” hinges to the door 100mm from the top and bottom and fix the door to the door frame. Check for operation and make any adjustments necessary before fitting a lock or latch. For the window, we recommend installing Perspex (available to order from Mitre10) rather than glass for safety, and weather sealing it with silicone. If painting architrave, seal it after as paint does not take to silicone.
Finally, add a protective stain or paint finish. If you prefer the treated pine can be left to age naturally to an attractive finish. Your Mitre10 paint department will be able to show you a range of finishes and colours to complement the setting.

Tools for the Job

• Power Drill and Bits
• Power Saw or Hand Saw
• Measuring Tape
• Pencil
• Spirit Level
• Sting Line
• Carpenter’s Square
• Sliding Bevel
• Hammer
• Spade
• Tin Snips

Material Checklist

• Timber
• Treated Pine Kiln Dried Rougher Header F7
  • Stumps - 4-100 x 100 x 600mm (or to suit site conditions)
  • Bearers - 2-100 x 100 x 1800mm
  • Sole Plates - 4-250 x 50 x 250mm
  • Joists  - 5-100 x 50 x 1800mm
  • Fascia Boards - 4-90 x 19 x 1500mm
  • Door Frame - 2-90 x 19 x 1500mm + 1-90 x 19 x 600mm
  • Window Frame - 2-90 x 19 x 450mm + 1-90 x 19 x 600mm
  • Fascia Capping - 4-70 x 19 x 1200mm
    
    
    
• Standard Dressed Pine
  • Wall Plates - 4-70 x 35 x 1800mm + 4-70 x 35 x 1660mm
  • Studs - 20- 70 x 35 x 1430mm
  • Roof Battens - 4-70 x 35 x 18000mm
  • Plate Blocks - 4-70 x 35 x 847mm
  • Rafters  - 3-90 x 35 x 2700mm (Cut 6 pieces)
    
    
    
• Hardwood
  • Temporary Bracing - 4-50 x 25 x 3000mm
    
    
    
• Yellow Tongue
  • Particleboard Flooring  1 sheet 3600 x 900mm
  • Exterior grade plywood 1-1500 x 370 x 12mm thick
    
    
    
• Hardware
  • 75mm galvanized bullet head nails
  • 50mm galvanized bullet head nails
  • 65mm galvanized flat head nails
  • 60mm galvanized roofing nails
  • 6 gang nail plates
  • 1 pair 150mm “T”: hinge and screws
  • 1-2 thick Perspex to suit window opening
  • 5 sheets corrugate zincalume iron roofing 1.156mm
  • 1- zinc zincalume iron capping 1800mm

There can be a range of variables in your materials so it is best to check with a helpful Mitre 10 staff member who will give you the best possible advice.
For a detailed MitrePlan on “Plant a Healthy Vegetable Garden” follow the link or pick one up at your local Mitre 10 store.