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Modular Castle

by Gary James

Modular castleWhat more could a Bretonnian or historical wargamer want than an imposing castle from which to sally forth and defend to the death against a savage enemy? Many commercial castles are just too expensive or simply not big enough to be anything more than a table ornament. I hope to show you that it's easy to make your own.


If you are not familiar with the anatomy of a castle then the Web is the ideal place to polish up your knowledge. One resource I can recommend is the excellent Castles of Wales web site. When you know your barbican from your donjon you are ready to begin planning your castle.

Construction approach

The featured castle is a modular design, by which I mean the wall sections, towers and gatehouse are separate components which are not joined together. This has a number of advantages. First, it makes the castle more versatile - you can add further sections at a later date, and set it up as a long fortified wall to represent part of a much larger castle. Second, it makes storage easier. Third, it allows you to substitute different sections for different scenarios or to insert a ruined wall section should the attackers breach your defences.

The castle is made up of three types of component - a gatehouse, wall sections, and towers. This section will deal with the construction of the gatehouse and wall sections. The second part of this project discusses towers.


  1. Polystyrene (styrofoam) sheeting in 1 inch and 2 inch thickness, or thereabouts

  2. Polyfiller (wall filler, spackle)

  3. MDF or other boarding for the bases and drawbridge

  4. Fine modelling chain for the drawbridge

  5. PVA glue and cocktail sticks for assembling the polystyrene

  6. The usual sand, glue and paints for finishing


All of the components are made using the same basic method. The shape of the component is made out of polystyrene, covered with wall filler, and then detailed by scratching a block pattern into the surface.


The dimensions of the castle are probably not crucial, but you should check your chosen game rules to see whether there are any specific guidelines for fortified walls and castles. Otherwise, go for a height which is sensible given the scale of your system and the practicalities of modelling and storage. In the case of Games Workshop's Siege rules, the height of the walls does not matter at all (unless you want to use their commercial siege engines and ladders), but you should make wall sections of about 12 inches length. My castle has 8 inch high (to the top of the battlements) by 14 inch long wall sections (12 inches seemed too short in proportion to the height). I based my castle height on an estimate of the walls of Lincoln castle (of course).

The dimension that is crucial is the thickness of the walls, or at least the width of the wall-walk on the top of the walls. You'll want to be able to stand your miniatures on the tops of the walls, so make the wall walks (tops of the walls) deep enough from front to back to accommodate two ranks (a rank of attackers and one of defenders).

For Games Workshop miniatures this means making them 2 inches deep at least.

Basic construction method

My castle walls and the gatehouse are made from polystyrene sheeting (styrofoam, bead board) cut to the basic shape of the structure. They are then covered with polyfilla (wall filler, spackle), sanded, and when dry a brick pattern is etched into the surface.

Gatehouse and walls

Modular CastleSince the gatehouse incorporates a section of wall at either side of the entrance I will use this to describe the construction of walls and the gatehouse itself.

Some terminology

To ensure we are all talking about the same thing here is a quick overview of castle terminology that I will be using:

Wall walk - The walkway on top of a castle wall, to allow soldiers to patrol, lookout and shoot at the enemy.

Battlement - The low wall built on top of the wall walk at the outer edge to provide some hard cover for soldiers.

Crenelation - A battlement with the traditional block-and-gap pattern providing slots to look and shoot through.

Crenel - The 'gap' part of the crenelation

Merlon - The 'block' part of the crenelation

Wall designs

simple wall designI have made two different designs of wall. The simplest design is a sheet of 1 inch thick polystyrene cut to 14 inches wide by 8 inches height. The crenelation is cut out of the top edge of the wall. When deciding on the size of the merlons (blocks) and width of crenels (gaps) there are a couple of points to bear in mind. First, you will want the battlement to have a symmetrical pattern, so start from the middle and mark outwards.

Second, if you are going to use a Dremel or similar tool to sand down the walls (highly recommended) then make the gaps wide enough for the attachment to fit in.

Modular CastleI use the small Dremel drum sander attachment to sand off the crenelation, and so I made the gaps wide enough to take it and still leave some filler on the model.

My second wall design is more elaborate. I used 2 inch thick polystyrene for the main body of the wall. Then I added a battlement by cutting 1 inch thick polystyrene to give the crenelation. To make the wall walk wide enough I added a lip to the inside edge, again made from 1 inch thick polystyrene.

Modular Castle

Building the wall and gatehouse sections

gatehouse front viewThe gatehouse is made up from a basic polystyrene shape cut and glued together with PVA glue or a glue gun. Cocktail sticks are used a 'nails' to fix parts together.

The small towers are the cardboard tubes from kitchen foil, cut to fit the wall. The turrets on top of the tubes are made from polystyrene.

Gatehouse rear viewThe gatehouse was also fashioned from 1 inch thick polystyrene. The drawbridge chains run through tubing from a plastic pen barrel to avoid cutting into the polystyrene. I ran a hot skewer through the polystyrene and glued the tube in. The drawbridge was made from MDF boarding, and fixed using a simple pin hinge. See Gorka Morka fort 2 for details of a pin hinge.

Of course the polystyrene is not strong enough to take the drawbridge pin hinges. The pins locate in two small blocks of MDF, one on each side, and these are glued to the polystyrene walls.

Cover your structure in polyfilla

This is where things get a little messy...

Cover with fillerCover your wall or structure with wall filler (spackle). Use a knife and spread it as smoothly as possible.

The approach to use depends on how you intend to sand down the filler when dry. If you have a Dremel or similar to sand the model down with then go for getting a thick coat of filler and don't worry if the crenelation is barely recognisable beneath the filler. A Dremel mini sanding drum attachment cuts off the excess filler in a flash.

If, on the other hand, you are going to have to sand it down with a file and sand paper then make your life easier by getting the finish as smooth and even as possible. The best way to do this is to leave the filler until is starts to dry, and goes to a modelling clay type consistency. At thispoint wet your knife and smooth the filler off into the right shape. This saves a lot of sanding later.

When the filler is dry sand it down with a Dremel, sandpaper and a file. Don't get too smooth a surface - a finish ridged by the file looks more realistic.

The block pattern

Block patternI wanted a realistic blocked finish to my castle. I achieved this effect by cutting a block pattern into the filler. You can do this in two ways. The first way is to use a nail, pointed knife or similar and scratch the pattern in. The easy way is to use a Dremel again with one of the engraver/cutters. I tried both.

The easiest way is to use the Dremel cutter, and I used Engraving Cutter 113. This has a square end and makes a nice notch shape. It also makes a lot of dust. Whichever technique you use mark your lines out roughly with a pencil first to ensure you don't get to the top or bottom and find that you have an awkward piece of wall left that is just larger or smaller than a row of blocks.

Remember that arches, windows and doorways have header bricks running around them like this arch on the inside of the gatehouse.

You may find that your filler is a little thin here and there and your cutter breaks through. Don't worry about this, it all adds to the stone effect when painted.

When you have carved the stone pattern in cover the whole model in a coat of slightly watered down PVA glue. This gives an extremely tough finish to the filler once it has dried.

Painting and finishing

Painting the castleThe walls and structures are all sprayed black and then dry-brushed with dark grey, building up to light grey and finally a very light brushing of white. This enhances the block pattern.

The drawbridge chains run through the pen barrel tubes and connect to a simple turning mechanism made from a bamboo skewer with a Games Workshop Fantasy chariot wheel on each end. This turns in two small pillars cut from MDF and glued to the gatehouse. The gatehouse roof has some decking made from balsa wood with a planking pattern marked into it with a pencil.


The sections are mounted on MDF bases. The walls overhang their bases by about a quarter of an inch but on the towers, the bases protrude about a quarter of an inch. Thus when they are placed together the wall sections sit on top of the tower bases slightly and this helps keep everything together on the tabletop.


The bases are covered with PVA glue and then sand. When dry, the sand is given a coat of very dilute Snakebite leather paint (mid brown) diluted 50:50 with water. It is then dry-brushed with light brown to give a sandy, stony effect. Patches of static grass are then glued here and there.

The 'ivy' growing up the walls and towers is made from plastic fish tank plants fixed into an ivy-like growth pattern with a hot glue gun. Part two of this project deals with castle towers.

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