There is a house where every nest sits on the wall. In the corners, under the beams, on the bare concrete. Not one of them on the nesting planks.
What is going on there? The birds have already said it plainly. They are happy to live in your house. They are not happy to live on your planks.
What you are actually looking at
The birds are there. Nests are going up. They are just going up in every place except the one you built for them.
You climb up and go plank by plank. The surfaces are clean and bare, nothing on them. The nests are in the wall corners, under the beams, on the concrete.
Some owners decide that is fine. A nest is a nest. But pull back and look at the whole floor. That entire run of planks is sitting empty. You paid for that surface and none of it is doing any work.
The wrong read: thinking it is the sound, or the positioning
Most people go looking at the sound first. Change the internal sound, add a few tweeters, buy a bottle of aroma and spray it around.
I took that detour myself. Sound is the easiest thing in the house to change, so it is the first thing a worried man touches.
But go back to that picture. The birds came in. They flew around inside. They built on your wall. So they are not failing to find your house, and they are not failing to hear you. They went up there, and they said no.
Changing the sound over and over, buying aroma over and over, and the planks have never once been washed. That is backwards.
What is actually wrong up there
There are only a few common answers.
One, the timber itself is wrong. Some woods carry a heavy smell and were never suited to being nesting planks.
Two, dust and dirt have built up until the whole surface has gone dark, and dark planks put the birds off. While we are here, grooves are not a case of more is better. More lines means more gaps, and dust settles into the gaps. You end up building a home for dust.
Three, the planks have gone mouldy.
Four, something has been added on top of them. Stainless steel mesh, plastic mesh, aluminium sheet, straw mats. None of those. They look like they give the birds another surface to grip. What you actually get is long term trouble, and the birds vote with their feet. They simply do not nest on them.
How to tell whether there is mould
Take a torch up there. Early on you will see a chalky greyish white film sitting on the surface. Later the plank starts going black, and it feels soft under your hand.
The line that matters most here is this one. By the time you can see the mould spots, it has already started getting serious. Not seeing it does not mean it is not there.
Mould did not grow on the day you noticed it. It grew until it was big enough for you to see. So waiting until you can see it is already a step late.
And a tree carries mould on it from the moment it is cut down. Nail those planks up and you have carried it into your house. New planks are not clean planks.
The order to check in, and you cannot reverse it
One, find the water. Mould always has a reason behind it. Is the roof leaking, is water collecting on the floor, are the walls seeping, is the misting system running all day. Leave those alone and your new planks go the same way in a few months. What you replaced was your money, not the problem.
Two, then look at the planks themselves. How dirty, how far the mould has gone, whether anything has been added on top.
Three, fix the water before you wash. Do it the other way round and you are washing them and then soaking them again.
Four, deal with the marks on the ceiling as well. A pair of swiftlets remembers two marks. The nest position on the plank, and the patch of ceiling their body rests against. Wash the plank and leave the ceiling and the job is not done. Plenty of people wash, wait a long time and see nothing happen. This is where they are stuck.
Not one of those four steps costs you anything.
When equipment finally comes into it
Now we can talk about washing.
My 2012 book said planks do not need washing unless they are very dirty, because washing makes them damp and mouldy. Today I say the opposite. Anything that has never been washed needs washing, whether your house is new, five years old or ten.
The reasoning has not changed. Wash with ordinary water and the planks really do go mouldy. What changed is the tool. There are products made for nesting planks now that deal with it without damaging the wood, so the answer moved with it. Ours is called Meranti+ Nesting Plank Enhancer. You spray it, you do not climb up and wipe plank by plank. It holds the mould off and it takes the smell out. It came out of my father’s swiftlet house and its mouldy planks.
You do not have to take my word for it either. Test it on one plank. Spray clean water on one half and Meranti+ on the other, then go up and look three days later. Swiftlets will not do you any favours, and neither will the wood.
But the order stays the order. When you see mould, do not rush to pull planks down and do not rush to order anything. Work out where the water is coming from first. That is what the MDK Swiftlet House Diagnosis Method keeps coming back to. Diagnosis first, prescription second.
One more thing while we are on planks. Do not spray things onto them. I wrote that one up on its own, in can I spray hormone on the nesting planks.
Your next step
Here is the free thing you can do today.
Take a torch up and go over your planks, the ones that have never held a nest most of all. Look for the chalky white film, look for blackening, feel whether the wood has gone soft. While you are up there, look at the floor and the wall corners for a damp patch that never dries.
If you are not sure, take two photos. One of the planks, ideally catching both a section with nests and a section that has always been empty. One of the dampest corner in your house. Send them to us and I will look at whether this is a plank problem or an air problem. Free, and you do not have to buy anything first. If we need more after that, we will ask you then.