Last week, I presented tips on farm building design from engineer Maurice Morrin. This week, I went with Maurice and his brother Austin to look at a yard which the two designed at Downings North, near Prosperous, Co Kildare. The brothers operate as A and M Morrin Planning and Design.
The sheds were built by father and son Malachy and William Henry who run a suckler herd. The sheds, and new silage pit, were built under the Farm Waste Management Scheme in 2007. Malachy was on hand to show us around. Originally, this was an outfarm with an old cubicle house and manure pit. The latter is now used for storing silage bales, etc.
On the left is slatted accommodation on each side of a central feed passage, while the shed on the right is a lie back area. Suckler cows are housed on the slatted area on the right hand side of the passage and have access via two doors to the lie back. There is space for about 30 cows on the slats. The slatted pens on the left are used for young stock. The sheds extend back for three bays.
The combined span of the two slatted sheds, the feed passage and lie back is over 31m (103 feet). Covering this by one span would have resulted in a roof that was very high at its apex and probably with a shallow roof angle. Instead, the Morrins recommended this design of two roofs. These feature a 15 degree angle which is preferable.
The design also facilitated a large lie back area, which the Harneys wanted. It gives shelter to the feed passage and means that the shed is square with the pits and does not protrude too far back into the field. There is a crush at the front of the shed, which William made up himself.
There is more awareness now among farmers of the need for good turning space and access for tractors, lorries and other vehicles. William Harney requested this wide working area between the silage pit - which is on the left - and the cattle sheds. At 17.5m (58 feet), it is generous.
The feed passage is significantly wider than most at 8m (26 feet). It makes use of the diet feeder and any subsequent pushing in of silage straightforward.
''I often see passages where the barriers are dented because a tractor wheel backed into them when silage was being pushed in,'' Maurice Morrin said.
''That wouldn't happen if the passage was wide enough. Here, we weren't joining up the sheds anyway, so there was no problem having good width.''
There are overhangs over the feed passage, leaving a 3m (10 feet) gap at the top which certainly ensures good ventilation. ''The silage doesn't have time to get wet,'' Malachy said.
It's a good idea to divide a slatted area into pens if possible, Austin Morrin noted. ''If total animal numbers are low, stock can be put into one pen and that ensures that dung will be walked down into the slats, keeping the cattle clean.''
Each slatted area is roofed by a lean to. It is supported by IP200 stanchions, which are 203mm x 102mm (eight inches x four inches) as laid out under the Department of Agricluture specification.
Behind, we see stanchions holding up the big lie back shed. It is a portal frame spanning 14.1m (46 feet) so these stanchions are carrying a significant weight. They are 305mm by 165mm (12 inches x six inches) in dimension.
Meanwhile, the feed barriers are hinged at both ends giving an alternative route out for livestock, if needed. ''Opening barriers are a good idea.''
The lieback area is big, measuring 14.2m by 14.1m (46 by 46 feet). The floor has a rubber mat covering and the Harneys are pleased with how it is performing.
The Harneys went for the rubber matting to save the cost of buying and spreading straw and the subsequent cleaning out and spreading of dung.
It also means that no storing is required for straw and labour is reduced. The matting cost approximately €6,000, Malachy said.
William cleans the floor every second day over to the slats, using a rubber scraper mounted on a light MF165. The tractor wheels are not damaging the matting, Malachy said. Cleanliness of the shed floor is also helped by the good slope down to the slats. The 1:40 slope gives a fall of 360mm (14 inches) over the 14.1m (46 foot) span. The cows are staying clean. There is a view among some livestock specialists that a lie back should span at least 25 feet, Maurice said. ''If not, the cattle won't always lie in it - some will lie on the slats instead. At less than 25 feet, the cows see it as more of a passage than a lying down area.''
There are no block walls here, all are mass concrete. Block walls have no role in a farm shed, Maurice said. ''It's too easy when scraping or cleaning out dung to tip a wall and - if it's blocks - knock it down.''
Bracing is important for giving a shed strength. Some farmers try to reduce the cost of a building by saving on steelwork. This angle bracing gives rigidity to the rafter and pillar. Without it, a shed will flex and sway to a greater extent in strong wind.
The angle bracing can be relatively important, especially on bigger, higher sheds, Maurice said. The cost of it is very small in the overall cost of a new shed.
''I have seen sheds in danger of collapse. The concrete walls have cracked and broken around the pillars because the whole shed is moving so much in the wind.''
Some farmers and building contractors argue that the Department specifications are higher than necessary. The Morrins don't agree. ''Most of the time, when you put an engineering specification on a shed, you will then see that the Department of Agriculture specs are spot on, Austin said.
''The grant specs are not wasteful; 95% of the time they are on the money.''
Meanwhile, this bracing is unobtrusive and won't get in the way of machinery or loaders, etc.
The roof cross bracing provides rigidity in a different plane.
''If there is no cross bracing on a big shed, eventually you will round holes in the roof under the nails. That indicates that the shed is moving in wind - and the sheeting is holding the shed together. Cross bracing stops that movement.''
The top of a shed like this can move by an inch without any problem.
Again, this cross bracing is unobtrusive and out of the way. Note, there is also cross bracing standing vertically between pillars - you can see it in picture 5. This gives good protection to the concrete walls by preventing the stanchions from flexing.
A portal frame has no internal pillars and the weight of the roof is supported by rafters and pillars - so bracing is important. The apex bracing prevents excessive flexing of the rafters.
Here, we see the knee bracing fitted where the rafters sit on top of the stanchions. This is the more important of the two bracings, Maurice said. but it is occasionally omitted to try reduce costs.
Maurice Morrin, Malachy Harney and Austin Morrin. Malachy said that his son William feeds the cows in the evening after work; it takes 20 minutes. ''There is no dirt and no mess.''