Fascias-style guttering leak internally

Fascia-style gutters causing water to run into the building

Guttering can be a hidden leaky building danger in many ‘low-risk’ homes

The perfect storm that culminated in the ‘leaky home’ fiasco was caused by a number of products and processes being introduced into the NZ housing market with totally inadequate testing, validation or approval.

Untreated timber, no cavities, untested leaky cladding systems, leaking windows, complex designs, reliance on sealants… the list goes on.

If you want help to find and resolve leak and decay issues in plaster clad homes, contact Moisture Detection Company for assistance. They have solutions to manage problems associated with fascia style gutters.

Moisture Detection Company use their patented Mdu Moisture Detection Probe System to investigate and provide hard evidence on the moisture, decay and the timber treatment condition of houses.  

Moisture Detection Company help plaster clad homeowners to diagnose, repair and manage leaks and decay at minimum cost and avoid the need to re-clad.

You can contact MDC on 09 271 0522 or click the link above for more information.

One of the biggest and least well known contributors to leaks is the fascia-style guttering known as Taylor or Klass fascia which was hugely popular due to the sleek stylish appearance.  If you drive around many of the houses constructed in this era, a large number still have this system.

Fascia-style (hidden) guttering systems have a high risk of allowing leaks to come into building walls and cause rot and leaky building syndrome. Because of their design and construction, small defects of installation, or blockages can cause overflows directly into the walls.

Fundamentally, the problem is that the internal lip of the gutter is usually lower than the external lip so that when it overflows, the water can run accross the soffit (if there is one), and into the wall and ceilings.

Often, where a valley in the roof runs into the gutter, the internal edge is notched even lower which becomes the first overflow point. If there are any blockages, excess rainwater during heavy rain will overflow back into the house, often without the owner being aware.

The low point in Taylor Fascia where it is notched at a valley entry

This is a particular problems for owners of plaster clad houses built from 1992 to 2004 where there is unlikely to be a cavity allowing the water to drain away, and the timber is likely to be untreated or undertreated.

We have seen virtually the entire internal framing of the back wall of a house rotted away behind the gib because of persistent overflows of the gutter.  Many people aren’t aware that the decaying leaves which block gutters and downpipes often house particularly agressive decay fungi which can cause accelerated rot when overflows wash it into the house.

In traditional externally-mounted guttering systems, these are designed that if there is a blockage somewhere, water will overflow away from the building. This does no harm to the building, and will alert the owner to a problem.

The Mdu Moisture Detection Probes installed in a house, will pin-point leaks that could be caused by faulty or blocked gutters so that the problems can be addressed.  Installing Mdu probes should be the first step that any owner of a plaster clad house should take when looking for potential leaks anywhere.
Ideally, the entire fascia gutter system should be replaced, however this is an expensive excercise.  Often we can just install effective overflows at critical points, which divert water away from the house if the gutters are threatening to overflow.
For more information contact Moisture Detection Company.


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20 Responses to Fascias-style guttering leak internally

  1. David says:

    I have these gutters in my house. I have overflows installed. One next to every down pipe. One further up in problem areas where the eves are small.
    The overflows are like a chute that deliver water from the side of gutter to out the underside of the eve. They move a lot of water in heavy rain. This level of rain would overflow an external gutter too I think. I’ve also seen a standard gutter overflow into the wall when full of leaves.
    I have gutter guard installed which increases the time I need to clear the gutter and greatly reduces leaves but still get smaller stuff. I clean the gutters every month or 2 and keep an eye depending on season.

    I feel the gutters in my house are adequate with overflows and maintenance in a house with eves and cladding that has ventilation (brick and weatherboard) such that an occasional small leak will generally run back out or dry out.
    I think in cases like mine it could be worth trying overflows before changing the whole system.
    I like the look too so persist with mine

  2. ray smith says:

    Thanks to all submitters. I’m replacing our Taylor/Facia/Spouting. My builder has done a few. Will cut 32mm off Soffit, then fix a Treated grooved Facia and attach standard spouting/downpipes. It’s sad the neither BRANZ nor Dept of Building aren’t taking a much higher profile on this Issue?

  3. ray smith says:

    I have the same problem in 2020. These issues will only get worse with global warming downpours. Due to the proximity of the Fascia to the spouting, heat build up causes
    excessive expansion/contraction that stresses joins and buckles the spouting. Furthermore due to the design internal spouting has minimal fall to down pipes. Down pipes can only run 50% full similar to drains and in torrential downpours rainwater overflow discharges into the soffit and as previously stated can/will migrate into the structure. Replace it with standard fascia and external spouting. Our Quote is approx $15,000

  4. Gia Frank says:

    Live in the US and houses built in the 70s have this internal gutter system that’s failing all over the neighborhood. My house is a 2 story ‘California Split’ style (though I live north of Seattle, ha), and has exposed rafter ends about 20 inches or half a meter long supporting the exposed and painted plywood decking with an angle cut on the exposed rafter ends. The exposed plywood is delaminating where the gutters overflow, at all the joints and downspouts which are also inadequate. We’ve had 3 estimates and they all say the gutters need to be cut back past the gutter edge, removing the angle on the rafters and also removing the rot and gutters. New fascia, THEN new external gutters. We are also planning a new roof after. Researching if a handy homeowner can chalk a line and cut those back before the gutter company comes, would save $1500 US.

  5. robert says:

    i bought 1 2yr home plastic fascia gutters. There is a spot where it drips along one back section and i suspect has been leaking for some time. When i looked, it has an expansion section that is weir like section that showed splits. A part time fix for winter which is, silicone. Summer i will dry gutter, install flashtack over this and bitumen paint, the section. This gutter is Plastic with a metal fascia. This fascia has what appears to be drainage areas which are like a small letter box slots along the very bottom of fascia that appear to be deluge overflow. I,ve always known gutters to be lower than the top of external wall, so any problems with water should run down external wall on the outside of house. Only damage should be to eaves/soffit. Unless your building has a internal box gutter of metal, definitely steer clear.

  6. Mark Thomson says:

    Great to see some facts about this flawed design that contributes so much to leaky buildings. It is a much bigger problem than the now banned pink Hardietex sacrificed as a scapegoat in the obfuscation & political arse-covering of the leaky building debacle. It is compounded by idiot builders who do not run the cladding up behind the soffit to provide a waterproof barrier to water overflows – a traditional requirement of this eave design that has been lost.

    I am just about to rip out the gutter/fascia from our fletchers built 90s house & put up proper gutter fascia. I will also Waterproof the back wall in-soffit and vent the soffit or maybe run it under the rafters at an angle & run another line of cladding up to cover the newly exposed wall. Thankfully our framing is all H3 and Boric & because I clear gutters every two weeks, leaks have been only in once every 30 year or more rainfall.

    Either way the message is clear – DO NOT buy a house with concealed fascia guttering. It is a serious flaw in waiting – not if but when.

  7. Eileen Smith says:

    Hi, I live in Auckland and have just had a building inspection on a small 2 bed unit, built around 1980, in Tauranga. The report stated
     Type: Internal concealed guttering.
     Condition: Defective Repairs & Maintenance Required
     Noted: There is heavy internal rusting.
     Recommendation: Replace as required
    I need to have a general idea as to what this might cost before I go unconditional. Not looking for quotes just ball park figure, so that I can decide whether to go back to vendors or not

  8. Phil A says:

    Power to the people. Nice to hear you guys sharing ideas to combat the ‘industry’ created by the leaky building disaster.

  9. Brendon says:

    I have the same problem, in a storm I had water pouring into the house above the windows in many places. I did have a little bit of debri in the gutter, so I installed gutter guard (mesh to stop leaves entering guttering). We had another storm a couple of weeks ago, gutters all clear and it happened again. Something not mentioned in the blogs above and something I am considering is to put many overflow drop down pipes straight down. They will allow water to drop down if a certain height is reached, under normal conditions water will still drain to downpipes. It may not look the best but it could be the cheapest option.

  10. Ant says:

    I’m surprised there are not more postings about this flawed design which appears to have been incorporated into NZ houses since the mid 80’s, all in a bid to hide gutters. The design fails at conception with the secondary stormwater flow path into the soffit cavity and commonly into the external walls.
    This is especially the case with aging (26 year old!) structures with soffit linings that may have slightly sagged. This then renders the designed secondary flow path to the soffit scuppers useless, with water heading towards the interior or even finding external soffit light fittings and filling them with water!
    We are spending a lot of money to extend the rafters, construct new fascias and fit conventional guttering to exterminate the hidden gutter system from our home, simply because they leak during storms, are difficult to monitor for debris build up and are difficult to clean.

    • Arne says:

      Like to hear the details of how this is being done, Ant…we are being forces into the same fix, with the problem compounded by the half-dozen pairs of starlings who annually squeeze into our gutters and build nests faster than I can tear them out!

      • sugadmin says:

        Yes these systems are defective in design and plagued by poor workmanship. Never trust them. All building products must be designed with an allowance for failure – so if they do fail, they don’t adversely affect other parts of the house in parts not easily discoverable like framing hidden inside walls.

        These fascia gutter systems are worst at valleys where the back of the gutter is lowered and when there is no soffit at all. Many are siphon systems so flow rates are slower and some don’t have enough outlets so overflow regularly even if built to specifications. My advice is to remove them. I know its expensive but repairing them is just a temporary delay to more leaks and they will be rusting away anyway, especially by the sea.

        Drill the rivets, pop off the outer shell, snip the brackets and release the gutter out. Bend what’s left of the brackets back and nog out the soffit to fix it and attach a new wooden fascia. You’ll need a slightly larger one (about 180mm) and only use H3.2. Check the roof overlap is around 70mm – if a bit less it will still work. Paint and fit new gutter on outside – when installing down pipes make sure you provide a relief – so if the main drains block it doesn’t back up and slow down the flow rates. If the fascias wrap around up the gable ends strip these off as well and continue the wooden fascia and install a flashing or cap tile.

        Or contact me and I’ll give you the name of a good plumber.

        • Monte says:

          Hi there I do have the same problem and very interested in your idea of total replacement with a external gutter system.Do you have any recommendation contact details for someone to talk to please. Regards Monte.

          • Robert says:

            I’m in the same situation. Any contacts who might be able to replace it in East Auckland please?

          • kingi says:

            Hi Monte
            I have the same problem,I like your idea of total replacement.
            Did you get a reply to your request for contact details,if so can you please share.
            regards kingi

        • Rob Haughey says:

          I’m in Christchurch and interested in total replacement. Our fascia gutter system is aged and the internal plastic gutter is leaking in places. Luckily it is not running towards wall but instead to outside edge and drips from (drainage?) holes in bottom edge of fascia. Hence those areas are rusting.
          For total replacement, is it always necessary to extend the rafters?
          Is a standard metal fascia an option? (eg Stratco).
          Does the soffit board also need to be replaced to reach new match new timber fascia?
          Any recommendations for a tradesman to do this job?

          • Hilary says:

            We see that your comment was placed in November 2017 so is more up to date than some of the earlier but equally disturbing comments. We wonder what advice you were given and what you followed it up with, Rob. This flawed, inadequate guttering system causes so many problems and so much anxiety. Are we able to contact you?

            Thank you for your comment and your reply, in advance.

        • Nick says:

          Thank you . I love your article .

          Similar problems here .

          Could I get the contact of your Plumber or contractor for the job ?

          Or how could I contact you .


        • Tamara Loots says:

          Hi there,
          You seem to be very knowledgeable, you also mentioned that you can recommend the plumber. My plumber said, he can’t do it. Would you be able to recommend someone, who can have a look at my gutters and help me to fix the problem? I will appreciate any help. Thanks, Tamara

  11. I was very pleased to find this site. I definitely enjoyed reading every little bit of it.It feels so nice to find somebody with some original thoughts on this subject. Really thankful to you for starting this. Thanks for sharing.

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