Sufficient to treat  a two bed cottage 40 feet - post paid UK only - Contents I pack of chemicals, dilutes to 25 liters & 36 Yards of copper foil

£25 cash, cheque, postal order or 25 £1 stamps see bottom of this page   http://thatch.org/consul.htm  for contact details

Copper Foil 5/32'' X 36 Yards (32m)  (118 feet) @ (.0012.5) thick. Long term release of trace copper salts.

 One pack will treat a 2 bedroom cottage approximately 40 feet long

Moss on thatch. Sorry this may seem long and complicated but it is important that you understand some of the complications involved - do your own research carefully 

This is usually caused by the roof being in a windless, damp, north facing area and is not a rare happening.

The presence of moss is not necessarily detrimental to the thatch. It can in some circumstances appear unsightly but it can prevent the roof from breathing. If required it is always desirable for a Thatcher to remove the moss by the best means he considers. Some success has been reported on the use of a copper strip on the apex.  However:

The most effective method for thick growths I have found is the application of one of the garden path moss/algae cleaners, spray on as  directed for a path, Or Wickes (the builders merchants) do a mould inhibitor. I cannot advise the use of these for legal reasons, It is what I do to mine however with a mask and goggles ! Try and keep off the roof with ladders, if you need to put a ladder on the roof spread the load with an old rolled up carpet or coir door mat under the ladder. Do not put any ladder on or even touch the ridge or areas with rods and spars.  The scaffold design for your access would be the same as that on a tiled roof. The important points are to keep operatives off the roof as much as possible, in particular the ridge and to protect the scaffold supporting points where they rest on thatch. Traditionally supports were protected by straw filled sacks. Old rolled up carpet is a good alternative. If any pointing, flue lining or rebuilding is expected it is important to prevent mortar debris getting onto the thatch, apart from being unsightly the lime can damage the thatch. Plastic sheeting right down the roof is essential. Allow for drips & leaching out over plants (& humans! - why I do not advise you do it) under the eave.

Any method of moss treatment. This may require two applications a year and it will probably come back - just repeat the dose and do in damp weather or the crust may break and damage the roof.
I am assuming  that the moss is a khaki colour slime mould lichen type (may have an ' Elks antler ' up to 1" vertical leathery growth) or just a light sticky covering, It is probably cup lichen  Cladonia brevis

If it is dark green and a thick mat of cushion type growth is allowed to develop over 1/2" thick it can trap water and prevent the roof from breathing it will require removal, try (after spraying and waiting) removal of a small area to test, Without removing the netting (if any) if more than 1/4" of the thatch surface comes away with it contact a Thatcher for advice, the one who thatched it if possible. Do not just rip it off, you will damage the roof. Even more important if it is a long straw roof   Brush off with a garden cane or broom, preferably without removing any netting.

Power sprays can be used for application, do not unless experienced use for moss removal, always use down the roof, never point upwards.

I have used ordinary household bleach and mixed up caustic soda powder, drain cleaner. Or make your own Oxy Bleach safer on the hands and roof than chlorine based ones. This has worked fine for me on severe cases. Again as it it not pleasant stuff I cannot advise its use in case someone sues me. The PH balance of the roof is important and must be maintained as slightly acidic. Flooding the roof with large quantities of chemicals can be dangerous to you, the environment and the roof. 

Oxy bleach.

For small area or testing add a half cup of baking soda to a spray bottle of water. A small squirt of washing up liquid can be used to act as a wetting agent as Moss and Lichen tend to be waterproof.

Pour a half cup of 3% hydrogen peroxide into the spray bottle. Hair dressing supply shops is a source. 'Hair bleach'. Mix and use

Spray the solution on the growth, you can also spray the home made oxygen bleach on grout, lawn furniture and anything else that needs to be cleaned, whitened, brightened or sanitised.

Mix a quart of hot water in a bucket. Add two cups of baking soda and two cups of 3% hydrogen peroxide to the hot water in the bucket. Use the mixture to soak the affected area.

After being told off by an owner who got some in his eye - It is what I do, not a recommendation for you !!  --- Cookers are hot so mind your fingers!

Over the last few years mosses and Lichen have become more prevalent on thatch It is a subject I personally have taken a great interest in, before I became a Thatcher I worked in the chemical industry and a relative was employed as an agro chemist, we have formulated a spray and sourced a easily to fit self adhesive copper strip. After 10 years of research I can now offer you

 Observation over many years has lead Thatcher's to understand that copper over head power cables where the moisture drip from them fall onto a thatched roof moss and algae does not grow on the thatch. Some Thatcher's now use strands of copper wire / pipe attached to the ridge.

 Copper strip is difficult and expensive to source and it may be a natural point for attracting lightning strikes, this copper foil is thick / wide enough with a life span of 15-20 years on a roof to give a adequate surface area for the minute amount of copper needed to be dissolved by rain water without being strong enough to conduct enough electricity to cause a hazard.

 It also has a very strong adhesive on one side with a protective removable backing paper to aid easy fixing into the wire netting loop around the wire strands and stick copper to copper you can also wire pin it on (see photo's) The ideal place to fix it is on the apex of the roof but I am not encouraging you as an owner to fit it there as the wooden patterns (spars / liggers) are easy to break, this foil is cheap & long enough to fix lower down on both sides away from ridge patterns. Thatcher's will know what I mean!! Discount available if you are a Thatcher, email me for details.

 My spray on solution dilutes down to 25 liters with tap water and contains Copper @ 5% among others. The spray is also a mild insecticide. To avoid high postage costs the ingredients are formulated only to contain active ingredients so it is dry no 'fillers' or water is used to impress with misleading quantity. The amount sent may seem to be small but it is effective. Even the spray should be kept away from aquatic life even though the quantity is small when mixed as recommended into a spray copper is dangerous to aquatic  life. The solution will be washed off by rain and will probably need two applications a year.  Spring and Autumn is best when the moss is damp. When mixing the crystals  with water use plastic containers and water at 60 degrees (c) filter through a coffee filter to avoid spray clogs due to re crystallization also add a little washing up liquid if needed to aid wetting of the moss and penetration into it. Apart from the copper the ingredients are formulated to be harmless to human and animal life when diluted and are slightly acidic PH 4, rotting thatch is acidic so the roof PH is kept balanced. Some other moss killers I have seen on the internet for thatch use use polymers to fix the chemicals, to me this defeats the object of supplying a continuous trace supply and could clog the surface - thatch needs to have air circulation or it will rot. 

The contents of the chemicals pack are hygroscopic and should be kept sealed or in a suitable plastic container either dry or in a pre mixed concentrate. Together with the warning label it is packed with.

Feel free to email me photo's of your problem area and ask for advice. see bottom of this page   http://thatch.org/consul.htm  for contact details.

                                         7 Days after spraying                                         Area to the right of ladder treated