Constructing Kali's main house

I used two basic techniques for making Kali's house rat proof.

1. Making sure that any corners which she could reach were smooth internal corners and that all supporting sections were on the outside of the house.
2. Lining any external corners or edges which she could gnaw with aluminium sections.

These are explained in more detail in the construction section below.

Materials and tools

All these materials came from DIY stores but you wont find all the materials in every store. Some of the items are only stocked in one particular store so be prepared to hunt round all the main DIY shops to get everything you need. The materials for Kali's house cost about £200.

	Material		size(s)		quantity
	Ply		6mm, 3mm		4m2
	Pine sections (square)		30x15mm		2.5m
	Pine sections ('L')		30x30mm		6m
	Aluminium sections (flat)		30mm		6m
	Aluminium sections ('L')		30x30mm		2.5m
	Aluminium sections ('U')		12x12		4m
	Wire mesh		Roll		5m

And a range of fasteners and fixings: wood glue, panel pins, round headed screws, 'T' nuts, bolts, hinges, door bolt, threaded bar, wing nuts.

No specialist tools are required but an electric drill, electric sander and heavy duty staple gun will make the job much quicker. Cutting the angles correctly is much easier with a proper mitre saw and G-clamps are useful for holding things in place while the glue dries but these is not essential. Other than these tools you'll only need a hammer, screwdriver, pliers, a wood saw and a hacksaw (for the aluminium) and a pair of wire cutters or tin-snips to cut the mesh.

Construction

Base section

This section is simply a plywood box with an open top. A pouched rat would be able to gnaw through plywood in seconds so this has to be constructed so the inside has no external corners for a rat to start gnawing on. All the supporting wooden sections have to be on the outside of the box.

1. Use pine square sections for the base frame glued and nailed together.
2. Glue and pin a ply sheet to the top side of the frame to make the floor.
3. Glue and pin four ply sheets to the outside of the frame to make the sides.
4. Secure the four edges of the box by gluing on pine 'L' sections. Remember to fit these to the outside of the box.

Upper level

This section is more complicated to put together but it is essentially a wire mesh box which is open both top and bottom Wooden frames, similar to the base frame make the top and bottom frames for this section. The corner pillars are made up of an inner aluminium 'L' section and an outer pine 'L' section. The wire mesh panels are sandwiched between the two 'L' sections and secured to the top and bottom frames. The inner aluminium 'L' sections extend beyond the bottom of this section so it can be slotted into the base section. This parts for this section simply bolt together and it is very unstable until the last piece is bolted in to place. One side is modified to include the door but the general principal of the construction is the same for all the sides.

The dimensions of this section are quite critical. The Inside measurement of the box must be the same, or slighly smaller than the inside measurement of the base so that the inner aluminium 'L' sections or the corner pillars can slot into the base.

1. Cut the wood for the top and bottom frames, ensuring that the inner dimensions are the same, or slightly smaller, than the inner dimensions of the base, but to not make up the frames.
2. Cut four pine 'L' sections to the correct length to form the corner pillars. Remember when working out their length that these will fit between the top and bottom frames not on the outside of the frames
3. Cut four aluminium 'L' sections to the correct length to form the inside of the corner pillars. These will be fitted inside the top and bottom frames and need to extend at least 20cm below the bottom of this section.
4. Cut the four mesh panels to the correct size for the sides. The mesh fits to the inside of the top and bottom frames but should not go all the way into the corner of the pillars. Stop about 5mm short of the corner.
5. Assembling one side at a time, and measuring very carefully as you go, proceed as follows:
• Lay out the wood for the top and bottom frames, offer up the mesh and stapel it into place.
• Clamp two aluminium 'L' sections into position. Double check the position of these pillars by slotting the clamped-up side into the base section. Adjust as necessary then drill holes through the aluminuim and the wood where they intersect. Use nuts and bolts to secure the aluminium pillars to the wood. (I used 'T' nuts which hammer into the wood and give a flush finish rather than normal nuts which protrude). Remove the clamps but be careful to keep the side square.
• Fit two flat aluminium sections to the top and bottom frames between the aluminium pillars. Drill and screw these sections onto the wood sandwiching the mesh in between. Position the bottom section so that it extends beyond the edge of the bottom frame. This will slot inside the base section and cover the place where the two sections join.
• Repeat step 5 for the remaining sides, using one pillar from the previous side as the first pillar of the side you're building, until you have a completed the box. (Remember to modify one side if you want a door.) The completed box should slot comfotably into the base.
6. With the mesh box slotted into the base clamp the four pine 'L' sections onto the outside of the pillars so the mesh is sandwiched between the aluminum 'L' section and the pine 'L' section. Drill and bolt these into place (again I used 'T' nuts for a flush fitting).

Roof

This section simply a wodden frame made from the pine 'L' section with the mesh stapled to the inside. It is secured to the top of the house with wingnuts.

1. Make a frame out of the pine 'L' section big enough to fit over the top of the main house.
2. Turn the frame upside-down and staple wire mesh to the inside of the frame.
3. Put the roof on the house and, woking from the top, drill a hole half way along each side of the roof right through the roof frame and through the top frame of the mesh box. Insert long bolts throgh these holes so they protrude through the top of the roof frame and secure the roof with wing nuts. Using wing nuts makes it very easy to remove the roof.

Fixtures and fittings

Shelves, levels and walkways can be made from thick ply edged with aluminum 'U' sections. The 'U' sections can be bolted to the mesh walls so that the shelves can slide into place and be removed for cleaning or replacement.