Here's a simple method for casting your own hypertufa cottage, or fairy house, for miniature gardening. I typically make my cottage molds out of urethane rubber and plastic so they are reusable, but after many request, I have come up with a simplified mold that anyone can make. I have kept this project very basic, but you can expand on it by adding integral pigment or carving details and textures in the mold.

Step 1: Overview

Time: 5 days

Cost: $50

Supplies You Will Need: half sheet of 3/4" rigid foam insulation, hot glue gun, glue sticks, utility knife, straight edge and ruler or tape measure, speed square, masking tape, marker or pen, rubber gloves, dust mask

Casting material: hypertufa, ShapeCrete, or stiff all-sand concrete mix

HYPERTUFA RECIPE:The amount of hypertufa mix you will need depends on the size of the cottage you're making. The basic mix I use is:

1.5 parts vermiculite

1.5 parts peat moss

1 part portland cement

water sufficient to make a firm, moldable mixture, plus a splash of liquid acrylic (about ¼ the amount of total liquid)

a handful of PVA reinforcing fibers

Step 2: Design Layout and Cut Out Parts

The example shown here is meant to be a guideline. The dimensions may change according to your design, but the basic parts and shapes are required. Remember to make the house body large enough that you can get your hand inside to pack your hypertufa. I would also recommend staying under 15" on any dimension with hypertufa of this thickness. Make sure to allow for overlapping glue joints where necessary.

On the roof side braces, start with the same roof pitch as the house body. Next draw lines offset the thickness of your hypertufa or casting media. The third line should be offset the thickness of your foam. When cutting out these pieces, remove the triangle consisting of the house body roof pitch. This will give you a guide to fill to, to ensure that your roof will fit on your house body.

Tips:

It also help to go ahead and draw lines where you intend your windows and door to be.

I typically make my eves hang over 1" or so.

Steps:

1. Plan and draw out all parts on your rigid foam insulation board.

2. Carefully cut out mold parts using a straight edge and utility knife.

Step 3: Assemble Your Molds

Assemble molds by applying a bead of hot glue to the edges of the foam, and attaching as shown in the photos. Use a speed square on your first pieces to ensure the walls are square. You will need to hold the pieces in place for a few seconds until the glue cools. Once assembled, reinforce the house body mold and bottom of the roof mold with masking tape, as shown.

Step 4: Casting Your Hypertufa or Concrete

Mix your casting media to a zero slump consistency. While supporting the outside of the mold with one hand, firmly but carefully pack the mix on the inside of the mold at about 3/4" - 1" thickness. Be sure to pack mix firmly around the windows and door knockouts, but be careful not to cover up the inside of them with mix. Square off the edges with your hands or use a small wood block as a guide. When finished, cover with plastic and let cure for the recommended time of your chosen media.

Step 5: Demolding

1. Remove tape.

2. Carefully cut the hot glue seams with a utility knife.

3. Pressing on the windows or door from the inside, gently wiggle the mold pieces off of the finished parts.

At this point, you may need to use a file or knife to clean up the edges or make the roof sit flat. You can also carve in texture, stain the parts, etc.