Building a rat shed

Over my years of rat keeping, my rats have lived in various places – sharing my bedroom, sharing the public spaces of the house, in a spare room, in an integrated garage, and in a detached garage. The one theme is that they have all been spaces that existed that have been filled with rats. Early this year, I decided that the time was right to build a space that was purely created for the rats. Project Rat Shed had begun!

I generally have a floating population of around 30-40 rats, plus any litters, rescues, or holidaying rats that may be keeping us company at any particular time. My shed needs to comfortably house not only these and their food and accessories, but have plenty of space for all my rat club and rat show related equipment too. Each space I have previously used for my rats had pros and cons, and so I wanted to try and get all the “best bits” from these for my new rat shed.

Deciding on size.

Most hutches and cages I use are around two foot deep, and so I decided that the shed needed to be at least eight foot wide. This gives space to have cages on each of the side walls of the shed and still give at least three foot of width in the centre to work in (I figured an amount would be lost from insulation etc).

Most of my rats are housed in hutches that are two or four foot long. I decided that in order to ensure I had ten foot of space inside, I needed a minimum shed length of twelve foot. This would allow all the majority of my hutches to line up against one wall of the shed.

I have had plenty of rat spaces before that have been perfectly adequate for the rats, but not particularly pleasant to spend time in due to feeling cramped or squashed up. One of my big considerations for the shed was that it should be a pleasant place to spend time in and invite guests into. So with that in mind, and after spending some time with squared paper drawing out potential floorplans for the shed, I eventually decided to increase the shed size from 8 x 12 to 10 x 16 foot.

The extra width gives me space to set up free-ranging tables in the centre of the shed, and have plenty of space for me and any guests plus my children to mill about and use the space without it feeling cramped.

Part of my agreement with my husband was that I could take over part of the garden with my new shed, but he shouldn’t have to see any rat food or “stuff” lying round the house. Since he has spent the last ten years putting up with every room of the house having a box of NERS possessions, a pile or rosettes, or a few spare show tanks lying around, this seemed like a fair compromise. So the extra length of the shed, I planned to partition off to use as a store for food, bedding and other rat-related possessions.


Location location location

We are fortunate to have quite a decent sized back garden, with neighbours on one side of us, a footpath directly at the back, and wild protected land on the third side. The downside is that the whole garden is on a slight slope, making locating a shed fairly difficult. Eventually, we decided to put the shed at the back corner of the garden, bordering the footpath and the wild land. The rationale was that it would then be mainly visible from the patio doors, and be as far away from the neighbours as possible. It would also be more conveniently located for connecting power to the shed too. Thankfully this part of the garden is not quite as sloped as the other side.

This location meants that the door looks down onto the house, and the windows look over to the side where the climbing frame and trampoline etc. for the children are, so I can watch them play while I’m inside the shed.


All about that base

There are several options for shed bases available.

Plastic: Low cost modular plastic bases are available for pretty much any size shed.
Gravel: An area can be flattened and covered with gravel to form a level surface for the shed.
Paving slabs: Paving slabs can be used to create an area for the shed
Concrete slab: A mould of sorts is formed, filled with concrete, and removed to create a large flat concrete slab.
Wood: Tanalised or pressure treated timber can be screwed together to form a large frame for the shed to sit on.

These materials can also be combined, for a bewildering array of alternatives. A wooden base built into a gravel area, concrete bearers on top of a plastic base, paving slabs arranged at strategic points under a wooden base. Everyone I spoke to had their own recommendation and reasons why any other option just wouldn’t work at all, and it was pretty overwhelming to try and decide what was for the best.

For a number of reasons, we decided to go with a concrete slab base. As our plot was on a slope, this provided the easiest option for building the base up out of the ground to be flat. The depth of the base is nicely insulating, and strong to carry what will be quite a sizable shed. Finally it provides less opportunity for nesting places for wild rats or mice, which to me felt like a big concern with wood.

The base itself was built to be exactly the size of the finished shed (10 x 16′). A base much bigger than the shed could cause water splashing down on the base to pool underneath the shed, potentially causing damp problems under the floor.

Because of the slope, the shed base is flush with the ground to the back left, and raised nine inches above the ground at the front right corner. In total, after digging the existing soil out and refilling, it took two tonnes of aggregate, and a tonne of sand, plus another tonne of paving slabs to complete. It’s solid enough that it will probably outlast the house, nevermind the shed that goes on it.

Insulation and ventilation

Mostly we think of insulation as a method of keeping something warm. While this is important to a degree in a rat shed, rats will cope with the cold quite happily. The bigger danger – and the bigger need of the insulation – is to keep the rats cool during the Summer, as hot weather can easily kill rats. Ventilation is another fairly major issue. The idea is not just to ventilate for the smell and fresh air, but all those little rats respiring adds lots of moisture to the air, and there must be ventilation or you will end up with damp inside your shed.

The shed style I had chosen is build as standard with a ventilation gap running the full length of the shed on both long edges, wherer the roof meets the walls of the shed. I also chose to have two opening windows. The majority of windowed sheds have static (non-opening) windows, but for an animal shed I felt that any windows needed to give me the opportunity to increase ventilation as necessary.

Options for insulation are varied. From lowest price to highest, the main options are: bubble wrap (foil coated or otherwise), rigid polystyrene sheets, rolls of glass wool loft insulation, or PIR insulation board.

Bubble wrap and loft insulation are easiest to put into oddly spaced gaps, such as those in the ceiling of the shed. Polystyrene is easy to cut to size and still fairly cheap. PIR insulation board provides the best insulation rating when comparing similar depths of insulation.

When insulating, it’s important to maintain an air gap between the outer wall of the shed and the insulation (this stops any condensation wetting your insulation). I also wanted to limit the depth of the insulation to around 40mm, to make it easy to line the inside of the shed after it was insulated. With that in mind, I decided to go for the PIR insulation board.

The insulation board is foil on one side, which I put towards the outside, facing the air gap. Cutting it for the wall spaces, which were pretty much all regularly shaped, was easy enough – the board simply scores with a stanley knife and then will snap easily. Insulating the ceiling, with irregularly shaped ceiling pieces due to the way the roof was built, was a hassle and took a long time. The boards can also make you quite itchy when broken up so care must be taken not to get bits in your eyes.

When insulating both the roof and the walls, I had to be careful to make sure that I maintained the ventilation gap along the full length, as it would have been easy to accidentally cover this and lose the ventilation.

I also went for a stable door, so I can leave the top open for air flow if I want, while still having the bottom locked so that children can’t go in and out without an adult present. Eventually I’ll make screens for both the windows and the stable door so they can be open without letting flies in, but that can be on my list of jobs to do when we head towards next Summer.

Also in the future I would like to add a solar powered extractor fan to the back of the shed, to increase the ventilation – these are fairly easily available and quite cheap to buy.



Once the insulation was all installed, we covered it in large sheets of plywood, which was screwed on to sheet the inside of the shed and cover all the insulation. I sealed the gaps between the boards with decorator’s caulk, and painted the whole thing magnolia. I live in a new build house which was entirely painted magnolia when I moved in, and the builders had left me a giant tub of magnolia paint – if I had the money, I would have bought something a bit more exciting, but it does the job.

The outside of the shed, we painted with two coats of blue shed paint. This protects it from the rain, and needs repeated every couple of years. The colour is nice and cheery, but muted enough that it doesn’t look like an eyesore (it blends into the sky on days that it’s not overcast).

The floor on the inside of the shed has been covered in non-slip lino. It has been very loosely glued down at the edges, but light enough that it can be easily pulled up to check the condition of the floor at intervals, to ensure that there are no areas with rot or damp.


Let there be light

Electricity for the shed is a definite necessity. We decided on two long striplights down the centre of the shed, with a double socket under the windows for plugging in a lamp and a radio. All of the cabling would be put into surface mounted ducting. Surface mounted feels safer than tunnelling the cables into the insulation, and easier to replace or upgrade in the future.

As the shed is around fifteen metres from the house, it was necessary to dig a seventeen metre long trench to hold the armoured cable. This had to be at least 450mm deep, and since the soil in our garden is mainly made of stones and gravel, it was hard and labourious work. Happily for me, my husband mainly did it while I was away at rat shows. The sticking point came when trying to get the cable into the house to spur off the socket – it apparently takes a much more powerful drill than you’d realise, and an even bigger drill bit than you think. The new drill bit to try this again has now arrived, so I’m hopeful that the electricity will be working in the next couple of days.


Fill ‘er up

The whole process of setting the shed up once it arrived took around two months of evening and weekend work, and although it’s not totally finished (the final bits of roof boarding need done, and the electricity isn’t quite hooked up), I decided that I need to introduce the rats as soon as possible. Summer was quite quickly starting to turn into Autumn, and I was aware that the rats needed to be out there before the weather turned to Winter, otherwise it could end up being too much of a temperature shock for them.

The rack of lab cages that I use for litters fitted just perfectly between the end of the shed and the first window, leaving lots of space for food storage boxes, some temporary cages, and eventually a workbench space for cage cleaning and suchlike.

My hutches are in stacks of three, on top of IKEA Lack tables. These were a couple of inches too tall for the new shed, so each table had around two inches sawn off the bottom of each leg. I kept the hutches an inch or two off the walls to allow for airflow. The hutches extend eight foot down the main wall, then turn 90 degrees, and continue another four foot across in an L shape. This leaves a large gap behind the hutches for storage.

Behind the hutches I keep all of my assorted bags of food, substrate, NERS equipment, show tanks and hire tanks, and similar ratty posessions. This gives me lots of space but keeps the main shed looking fairly tidy.

The rats seem to be thriving in the shed. After an initial period where they did drop a bit of condition, they seem to have begun to acclimiatise to the different climate in there. I have added a bit of extra linseed and hemp into their diet to give them more protein and oils to make up for the temperature being lower. And I am finding it so much more pleasant to tend to my pets in a bright and airy space overlooking my garden rather than being tucked up in a cramped bit of the garage with no natural light. It was a long and expensive journey but totally worth the years of saving.