5 Common Problems with Thatched Roofs

We have picked out five of the most common problems which cause a thatch roof to leak and outlined the best way to solve them. If you're having problems and your thatch roof is leaking, read on!

Problem 1. Leaking Capping

Symptoms: The capping (or ridging) is the section right at the top of the thatch roof. Sometimes a leak will come directly from the top of the roof and other times the water will trickle down the internal poles and make it seem as though the leak is from elsewhere on the roof - for this reason it is sometimes difficult to tell whether the leak is coming from the capping.
The Problem: Traditionally the capping is made out of a mix of cement, sand and crusher dust which forms a rigid capping. Because of the long, thin shape and expanse of the capping and the nature of the cement mix, cracking is almost guaranteed if expansion joints have not been fitted. Some thatchers fit a thin layer of plastic under the capping before the cement is laid although often this layer is punctured during the laying process and the plastic is therefore ineffective.

Cracked Capping
A capping in bad condition
Solution: Once the capping is laid it can be covered with a membrane and water-proofing solution. This layer water-proofs the capping and allows movement and flexibility as the cement base ages. The membrane and solution must be fitted according to the manufactures specifications to be effective. This solution can be costly (and certainly costs more than fitting a cement capping alone) but over time it is the most effective solution to capping problems as you will not have to call out a thatcher to repair the capping every year or so.

A layer of membrane being added to the capping
A newly repaired capping

Problem 2. Leaking Valleys

Symptoms: The thatch roof is leaking where two sections of roof meet from different angles (the valley section).
The Problem: Generally valley sections, even if not fitted correctly, are fine when the roof is first thatched. After a few years of rain and damp conditions however, problems start to arise. Valley sections bear the brunt of the water drainage for thatch roofs and experience a large amount of water flowing down them when it rains. They take longer to dry out than other sections of roof because of their angle and thickness and they therefore rot more quickly allowing leaks to form.
An inadequate, rotting valley
Solution: A proper valley "section" needs to be fitted to help the water drain form the roof quickly and prevent the thatch in that area from holding water and retaining damp. These valley sections can be fitted to existing roofs, the process involves stripping that small section of valley and fitting the valley section with thatch around it.
A valley with a valley section fitted allowing
drainage

Problem 3. Leaking or wind damaged Corners

Symptoms: The thatch roof is leaking at the corner or the thatch has been " lifted" by the wind and is falling out.
The Problem: Corners are commonly a problem for inexperienced thatchers as they are a difficult area of the roof to thatch. They are often therefore thatched too thin or with too little compaction.
A corner very thinly thatched
Solution: The corners of the roof need to be stripped and re-thatched. If you are in a high wind area hex-net can also be applied to the corner of the roof to prevent the wind from buffeting the thatch. This general problem is easily prevented by using an experienced thatching contractor.
The same corner re-thatched and covered with
hex-net

Problem 4. Inadequate Compaction of Thatch

Symptoms: Accelerated rotting of the thatch, thatch coming out of the capping, regular wind damage and generally endless problems with the thatch leaking.
The Problem: This problem is connected with all of the problems mentioned above and many others besides!  Inexperienced thatchers and thatchers who rush jobs do not compact the thatch properly on the roof. This causes endless problems and also puts your thatch at an increased risk of fire due to the extra oxygen in between the thatch stalks. The thatch MUST be applied to the compaction of 35 - 50 kg per square meter.
A roof with poor compaction
Solution: This is a very difficult problem to deal with and all depends on the quality and condition of the twines used to tie the thatch. If the twines are in good condition then the entire roof can be re-tension-ed and brushed to re-compact it. If the twines are in poor condition or are of poor quality then they will snap as soon as you pull them - in this case the only way to end your problems is to re-thatch the roof to adequate compaction.
Twines being re-tension-ed

The roof after re-compaction

Problem 5. Animal & Bird Damage

Symptoms: Thatch hanging out of the roof and small leaks.
The Problem: Thatch does not fare well in the face of birds and animals. In some instances where dealing with animals like baboons and monkey the damages caused are almost malicious - the animals will physically pull the thatch out of the roof. If your roof is badly compacted in the first place these damages will be exaggerated as the thatch comes loose more easily.
Solution: Whether the bird and animal damage is bad over the entire roof or only over sections, hex-net can be fitted to prevent a lot of damage. It is also important to keep trees pruned well back from the roof to prevent animals having such easy access to the roof or using it as a thorough-fair from A to B.
Hex-net fitted to the roof to protect from animal
damage

It is important to always call an experienced thatching contractor to help identify the cause of leaking thatch roofs and prepare a satisfactory long-term solution. To read more about thatched roof maintenance visit our website.

Comments

  1. There have always been ways to maintain the good appearance and durability of thatched roofs like those mentioned. Just like the usual roof types, thatched roofs must be constantly maintained and repaired to avoid damage. Home owners can brush their thatched roof several times to prolong its lifespan. If vermin damages or gullies appear, then, it is about time to call a professional thatcher to fix the damage ASAP.

    Laurelle  BaughmanLaurelle  Baughman

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    Replies
    1. Hi Laurelle,

      Thanks for your comment - it is right to mention that all roofs require maintenance and care - it is not only thatch that needs time and money putting into it occasionally. Also - it is sensible to fix problems while they are small and before they become a major expense so if in doubt - call a reputable contractor!

      Thanks for taking the time to read the article and commenting!

      April

      Delete
  2. Of all the problems in the list, I think the most difficult is animal damage. You are right that some animals can physically pull parts of the thatch easily. And some have sharp claws and talons like birds that can tear the thatch apart. One solution I find helpful is adding mud or clay to the thatch. That way, the thatch would stick together, protected from tearing and pulling by animals, and at the same time, help make the house cooler.


    @Kristopher Diss

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    Replies
    1. Hi Kristopher!

      An idea I haven't heard of before but it sounds like you've had success with it. Thanks for sharing!

      Delete
  3. I had some maintenance work done on our lapa by Werner Hendricks from Macassar, Strand. He has been in the trade for more than 25 years. He was on time for his appointment, his quote was reasonable, he started early the next morning and did a great job. Cell: 082 347 3201

    ReplyDelete
    Replies
    1. Hi Roy,

      Thanks for leaving your recommendation and thanks for taking the time to read our post.

      Delete
  4. In addition, one of the most common problems a thatch roof usually encounters is leaking. One solution to it is to regularly do maintenance on the drainage system to keep the materials from weathering and rotting, especially those near walls, because that’s where water may accumulate fast. It might seem simple, but it can certainly help the thatch roof last longer.



    @Pleasance Faast

    ReplyDelete
    Replies
    1. Hi Pleasance,

      You're right - it is hugely important to have a proper maintenance plan in place and to consult an experienced thatching contractor to help put this plan together. Drainage systems can be very problematic if not installed properly and cared for adequately.

      Thanks for reading our blog & taking the time to comment.

      Delete
  5. How do I get rid of the dust it causes. I try to clean the inside allot but my house stays full of dust.

    ReplyDelete
    Replies
    1. Hi Gerda,

      Thanks for posting - when was your roof thatched? It sounds like it might be an old roof or that the wrong type of thatch has been used for the climate that you live in. Old thatch roofs can have dust problems. If the roof is not very old perhaps it may need to be compacted and sprayed with a fire retardant spray which helps to bind the thatch together. However, not having seen the roof myself I cannot give a good recommendation as it depends entirely on how well the roof was originally built, the thatch type and climate.

      I hope you find a reputable and experienced local contractor who can help you.

      Delete
  6. Roofs like this look like they would need constant maintenance and repair. I can't say I've even seen roofs like this besides t.v. and pictures like these. Where is it that houses have this kind of roof structure?

    ReplyDelete
    Replies
    1. Hi Clarissa!

      Thatch does require maintenance but if thatched properly it is not a huge amount more than any other type of roofing.

      These particular roofs are in the Eastern Cape of South Africa but there are thatchers all over the world - thatching has been around since man began building his home ;)

      You can visit the website of the International Thatching Society to find out more about thatching all over the world - www.thatchers.eu

      Enjoy!

      Delete
  7. About a year and a half ago,my husband and i bought a house with a lapa attached to it. We have not had any issues with,but someone mentioned a lapa needed to be maintained on a regular basis.We therefore called in a registered "expert" who told us that the lapa will look as good as new after the maintenance.three weeks after the maintenance we have so many problems, the thatching is falling out and it is loose.we have called him several times but he just sent us the foreman and his men, not even showing himself after the complaints and our constants follow ups.they state that the people that didnthe original thatching about 15 years ago did it wrong. According to the registered "expert" capacity is a problem so we had to wait.now the foreman was here and they say that the only way to fix the problem is if we span fencing flat over the thatching which in our opinion will look like an informal settlement.we can then just as well break down the lapa.any advice in this regard?

    ReplyDelete
    Replies
    1. Hi Jaimee,

      Thanks for your post - I'm sorry that you have had a negative experience with your local contractor. It sounds like the roof needed a proper assessment before it was touched - in some cases, if the thatch is settled and doing it's job, it is better to leave it alone than maintain it "because thatch needs maintaining". It is difficult to say without seeing the lapa itself but it sounds like compaction and tensioning is the problem which has not been dealt with properly in the maintenance process.

      The only time we tend to cover the thatch with anything is if there are animals pulling out the thatch or it is in a high wind area (for example in a reserve we recently thatched the baboons were pulling out the thatch). In that case we tend to use chicken wire/ hex-net to cover the thatch, which is almost invisible unless standing close to the roof.

      In the case of your lapa I would not recommend covering the lapa "to hold in the thatch" - there is obviously an underlying problem in the thatching which needs to be addressed rather than covered up.

      When you say "registered" expert - can I ask if the contractor is a member of the Thatchers Association of South Africa?

      Delete
  8. Looking for a roof solution? Look no more! Check out roofing contractors bronx

    ReplyDelete
  9. Water coming from ceiling in "safe room"?
    abilene roofing

    ReplyDelete
  10. We recently started leasing a thatched cottage & I am now having dreadful lung problems. There is always a very fine dust covering the furniture despite my dusting twice daily. Can the inside be sealed to prevent this as sure this is what is affecting my health?

    ReplyDelete
  11. We recently started leasing a thatched cottage & I am now having dreadful lung problems. There is always a very fine dust covering the furniture despite my dusting twice daily. Can the inside be sealed to prevent this as sure this is what is affecting my health?

    ReplyDelete
  12. Do you guys also struggle with dust inside the house? Because I have to clean the counters and all the other objects every day because of the dust?

    The house is newly built so will it go away?

    ReplyDelete
  13. Do you guys also struggle with dust inside the house? Because I have to clean the counters and all the other objects every day because of the dust?

    The house is newly built so will it go away?

    ReplyDelete

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