Your birdroom roof needs fundamental repair. Do you call in a professional roofer? Not if you’re JON ASHBY! 

TWO things you definitely do not want in your birdroom are mice and damp and so maintaining the room in good order to stop it deteriorating generally, and to ensure it endures for many years, is critical. Patching and general repairs are ideally undertaken in the warmer months of the year when the days are longer, and when rain won’t defeat your painting or roofing efforts.

I have seen a lot of lovely birdrooms where fanciers are so preoccupied with what is going on inside that they have neglected the external parts where rot, for instance, has got in and is eating their shed away.

I also like my small birdrooms to look aesthetically pleasing from my house as I look down the garden, but of course this is not key when attempting to breed good birds. I am just a perfectionist in that regard.

When I constructed my smaller, second shed a couple of years back, I felted the pent roof and then immediately covered it with corrugated, bitumen roofing sheets. These last up to 25 years, the manufacturer claims, and so at £17 each or £54 for the three sheets I required, I knew this was a good value investment. But this left me with one shed with the black bitumen sheeting and the other with merely felt, an unbalanced look.

An impulse buy

These bitumen roofing sheets are 2m x 1m (6ft 6in x 3ft) and so don’t easily fit in a car. They also come in green. However, the other week I found a well-known DIY-come-builders merchants were selling them at £5 a sheet, the same black sheets but in a size that were 1m x 0.76m (3ft x 2ft 6in). Before I knew what I was doing – such is how I often begin projects – nine were in the back of my car, along with some specialist screws that come with built-in closing caps, oh, and two apex ridge tile sheets. 

By the end of the week I had installed these onto the small extension to the front of my main shed. This “porch” extension is 1.2m deep x 2.4m wide (4ft x 8ft), and so I could easily install the sheets with the aid of a ladder. However, I couldn’t quite screw down the farthest parts of the sheets without getting on top of the original, separate main part of my shed.

Now, being 6ft 4in and not the lightest of frames, I knew clambering up onto my shed roof was a tad risky in terms of weight. This main portion of the shed is 2.13m deep x 4.26m wide (7ft x 14ft) with a front-to-back apex.

I called the manufacturer who recommended I lay a scaffold board across the shed roof when getting up onto it, so as to spread the weight. But I was still not receiving assurances from them this would be enough. By now I was thinking, blow this, I am just going to sheet the rest of the main birdroom and so I took the plunge and had delivered nine of the 2m x 1m bitumen sheets, three ridge sheets and a 200 or more specialist screws.

It suddenly dawned on me that I have a number of builder friends, so I could easily borrow a scaffold board and an ACROW prop with which I could brace the centre apex section line of the shed. So, with a relatively easily installed ACROW in place (which I could just wind up until it clearly supported the shed roof right in the centre of the apex) and with a day booked off work that looked clear and dry, I began the final stage of Project Bitumen Roof. 

My neighbours had removed three large trees that had shaded my sheds at the bottom of the garden a couple of years back, but their presence had resulted in a felt roof covered in old moss. In fact, a lot of moss. First, I swept this off and remarkably filled a number of bin/rubble bags with it.

Call in Moss Bros!

The moss came away easily in most areas while others needed a bit more vigorous brushing. But in the end all of the moss was removed and I found the 10-year-old felt underneath in remarkably good health. I had already elected to again go over the top of this felt with the sheets, so I was relieved to find that it did not need changing before I did so.

Lining up the lowest sheets that had to be installed on the lowest slopes of the apex fall was key. I needed to be certain that the fall from these during heavy downpours did not result in the water rushing off and overshooting the guttering. Once these were lined up and secured in place with a few holding screws, I could now secure them fully using more screws. These sheets need to overlap by three corrugations so they deny water ingress laterally underneath them and are screwed down well along these joins, again to stop a strong wind getting under them but also to stop moisture creeping underneath. 

You can buy and add a foam blocker that closes off the gaps under the corrugated sheeting but I prefer air flow under them. I can revisit this decision at a later time. My sheets are so well screwed down I am not worried about the wind lifting them.

Once the lowest sheets were installed, I cut three sheets in half by measuring, marking and cutting with a sharp old saw that went through each sheet very easily. These then overlaid the first sheets down the slope and, of course, each other laterally and were screwed in place with a few screws and then permanently pinned down using many more screws.

Permanent fix

Finally, I was ready to install the ridge panels which overlap adequately along the ridge and I made certain were well screwed down, perhaps excessively so as I do not want to return to this roof anytime soon! By now I am working on a smaller scaffold board, so as not to damage any of the new sheets I have laid across the already installed roofing sheets at the lower levels. I was also able to finish off screwing the sheeting on the more recently added front entrance part of my new birdroom; the part I couldn’t reach a few days before and resulted in me needing to access the main shed roof.

Additionally, I had a bit of lead flashing left over from some building work that had a taken place at my home and I nailed this to the front of my shed to ensure water did not run back under the eaves of the main shed and between it and my porch shed extension (an eaves apron I think it is called). Over the top of this, I screwed on two planks of wooden board to act as a fascia and to improve the finish.

I am chuffed with the look and finish and believe this will prolong the life of the structure for many a long year to come. That these sheets last for twice the length of time of a good roofing felt makes them very appealing. 

Screwing down the sheets

It is not obvious to everyone where the screws go into the bitumen sheets. They must be positioned at the highest point of each rise in the wave of the sheets and not in the channels where the water flows down. The caps on the screws, closed once the screw has been screwed home, stop water running down the screw thread and into the material the screw is secured into and damaging/destroying/rotting it.

Jon Ashby is the show coordinator and publicity officer for Bedfordshire BS.