# Forum Home Renovation Waterproofing  Rotting Fascia behind gutter

## Timber21

Hello experts
I am looking for some advice before tackling a repair of a rotting fascia board. 
I have supplied some photos.
The issue is that I don't really want to go to the expense of removing the gutter and re-installing an entire new fascia. The rot has occurred because water splashes up from the downpipe which is releasing water into the gutter to be taken away by another downpipe further along. 
1. A wide view of the problem area..  
2. The fascia butts up to cement sheeting behind the gutter.  
I will need to remove and replace the decorative timber pieces (seen far left of Picture 2 near the brickwork and to the right of the small section of downpipe in Picture1) as these are both rotted at the bottom.
Ideally I would have liked to insert some aluminium flashing behind the cement sheeting, fold over the fascia edge and rollover into the gutter but this is not possible.
I was thinking of just installing the aluminium flashing over the fascia edge, butting up to the cement sheet edge and rolling over into the gutter...siliconing the joint where flashing meets cement sheet and any 'free' ends. 
While looking for supplies/advice in Bunnings, I was fortunate to have 'bumped into' a waterproofer (happened to be eavesdropping on my conversation with Bunnings staff).  
The waterproofer suggested the following:
1. Ditch the idea of using the aluminium flashing
2. Using Sikaflex Pro Multipurpose Sealant to run a heavy/wide bead along the fascia/cement sheet junction
3. Allow the Sikaflex to cure 
4. Paint 2 coats of Crommelin Exterior Grade Waterproofing over the joint and fascia edge extending a little way up the cement sheet allowing sufficient drying/curing time between coats
5. Paint with the required exterior colour. 
This sounds good to me but I am wondering if I should do a little more because: 
With reference to picture 2: 
Towards the left end of the gutter (near the brickwork) there is a small gap (approx.2-3mm) between the gutter and the fascia due to shrinkage in the rotting fascia. This gap extends (in a dimishing fashion) approx 20cm along to the right.
Because of this gap, water can run down between the fascia and the gutter and I am concerned it may cause more problems down the track. 
(Note: the fascia has only rotted approx 25mm from the top edge down in the section closest to the brickwork approx 10 cm in length. The rest of the fascia hanging below the gutter is essentially sound/firm to the touch and the rest of the fascia running to the right also seems fine)  
I am thinking of:
1. Applying some Earl's Wood Hardener to the rotted section of fascia, 
2. Filling as much as possible with Porion Exterior filler, 
3. Applying the Sikaflex and Crommelin as the waterproofer said above.
4. Adding a piece of aluminium flashing contoured to the fascia/gutter as originally thought and sealing again with Sikaflex where the flashing meets the cement sheet (I'm not sure of the best way to secure the underside of the flashing to the fascia to prevent movement...?silicone or more Sikaflex))
5. Re-attaching new decorative timber pieces and sealing edges/gaps of the timber with the Sikaflex
6. Final painting 
I would appreciate any advice/thoughts/suggestions. Is it overkill to try to attach the flashing? Perhaps I could just Sikaflex the gap between the fascia and the gutter? 
Cheers
Timber21

----------


## cyclic

> Hello experts
> I am looking for some advice before tackling a repair of a rotting fascia board. 
> I have supplied some photos.
> The issue is that I don't really want to go to the expense of removing the gutter and re-installing an entire new fascia. The rot has occurred because water splashes up from the downpipe which is releasing water into the gutter to be taken away by another downpipe further along. 
> 1. A wide view of the problem area..  
> 2. The fascia butts up to cement sheeting behind the gutter.  
> (1) I will need to remove and replace the decorative timber pieces (seen far left of Picture 2 near the brickwork and to the right of the small section of downpipe in Picture1) as these are both rotted at the bottom.
> (2) Ideally I would have liked to insert some aluminium flashing behind the cement sheeting, fold over the fascia edge and rollover into the gutter but this is not possible.
> (3) I was thinking of just installing the aluminium flashing over the fascia edge, butting up to the cement sheet edge and rolling over into the gutter...siliconing the joint where flashing meets cement sheet and any 'free' ends. 
> ...

  (1) All good.
(2) Use purpose folded zincalume or colorbond.
Why is it not possible ??
(3) Place the flashing behind the sheet.
If necessary cut the sheet (assuming not asbestos cement) about 30mm up from the gutter so the flashing can be slipped under.
(4) Advice from Bunnings and a waterproofer.
Definitely not a good idea on both counts. 
Most important, fit an angle on the base of the short downpipe so the water runs toward the main downpipe and does not splash.

----------


## Timber21

Hi Cyclic
thanks for the reply.
(2) I cannot get easy access under the sheet as it is fitted tight at both the junction with fascia/gutter and also the probable stud work of the roof which sits behind it. I also don't have appropriate tools/skills for cutting it.
I thought as the next best option (possibly manageable for a 'semi-skilled female') I could do the waterproofing as suggested and then use the malleable aluminium flashing (which comes in a roll from Bunnings) to fold over the outside. Have a lip which sits about 25-30mm up the cement sheet and seal the edge with the SikaFlex. Perhaps I could use some SikaFlex or Silicone on the underside of the flashing to act as a type of glue?. The ends of the new decorative timbers would sit over the top of the flashing and provide a little extra fixing power.
I thought this would create a dual-layer of protection against water penetration given I can't DIY the best solution. As long as water doesn't get under the flashing. At the moment with the fascia exposed at least it can dry but if the water gets under the flashing I am concerned it will sit there for too long before draining down between the fascia and gutter. I thought perhaps with the waterproofing under the flashing it would minimise the risk.
Could you elaborate on why the advice from the waterproofer is not a good idea? 
Adding the angle to the downpipe...I don't have a rivet gun or colourbond guttering but I could probably attach some of the aluminium flashing with some screws and then silicone the joints??? Does that sound reasonable? 
P.S. I have also come across a product called Earl's Wood Hardener which I want to use on the rotted portion of fascia to stabilise the wood which is left and help prevent further deterioration. Any experience/knowledge of this product? 
Cheers
Timber21

----------


## cyclic

No tools no skills makes it difficult.
Last things first, Earls Wood Hardener no idea.
To use any product like that you must first remove rotten timber and paint so tools and skills needed.
As to waterproofing over things like that, if that is all you can do then simply cover all joints with sika fc11, or, even cheaper, plumbers and roofers silicone, but as I said above, most important to make the downpipe flow along the gutter so it is not splashing, but I would be seriously checking the roof above the small downpipe as It may be leaking from there as well..

----------


## Timber21

Hi Cyclic 
I have some skills and knowledge (learnt from my father and as owner/builders of my home) but few tools other than basic. I know that the best solution would be to insert the flashing under the sheet but I certainly don't have the skills for cutting out the cement sheet. 
Earl's Wood Hardener does not require removal of the rotted timber. Apparently, quite the opposite... It supposedly hardens and stabilises what is there so that it can be more readily puttied/filled. So, I am thinking of using the Earl's and then some Porion to patch what I can get to.
I have already checked the roof, flashing and joints above and all is good. The exposed fascia to the right of the downpipe is also in good condition (just needs a re-coat). I think this may be because it dries out a lot quicker than the section under the eave.  
I have already made a preliminary inspection of the small downpipe to determine how to attach the angle as you suggested. Would you agree that fashioning a contoured, curved 'angle' with the flashing material as I described would be sufficient?  
Cheers

----------


## cyclic

> Hi Cyclic 
> I have some skills and knowledge (learnt from my father and as owner/builders of my home) but few tools other than basic. I know that the best solution would be to insert the flashing under the sheet but I certainly don't have the skills for cutting out the cement sheet.   
> I have already made a preliminary inspection of the small downpipe to determine how to attach the angle as you suggested. Would you agree that fashioning a contoured, curved 'angle' with the flashing material as I described would be sufficient?  
> Cheers

  For the downpipe, I would guess a 100x75x90 rectangle to round adaptor will fit which should be all you need to fit to the bottom of the downpipe to cause the flow to run along the gutter as opposed to splashing, as you say.
One screw will hold it in place or you can place to the existing downpipe.
I question if the gutter may be overflowing as shown in the marks on the lower facia under the gutter.

----------


## Timber21

Thank you...will look for that adaptor. I know what you mean but I think that may not give enough clearance underneath (i.e I think it will touch bottom of gutter. Anyhow, will investigate it.
No, the gutter definitely does not overflow. The marks you see are where drips of water seep between the back of the gutter and the fascia when raining. This is why I was thinking of also sealing that gap with a bead of Sika (sound ok to you?) 
I note you suggested the Sika 11FC. I have the Sika PRO and wonder what is the difference between the two and can they be substituted for similar result?

----------


## cyclic

> Thank you...will look for that adaptor. I know what you mean but I think that may not give enough clearance underneath (i.e I think it will touch bottom of gutter. Anyhow, will investigate it.
> No, the gutter definitely does not overflow. The marks you see are where drips of water seep between the back of the gutter and the fascia when raining. This is why I was thinking of also sealing that gap with a bead of Sika (sound ok to you?) 
> I note you suggested the Sika 11FC. I have the Sika PRO and wonder what is the difference between the two and can they be substituted for similar result?

  It is pvc adaptor, and shorten the downpipe if necessary.
Sika pro is ok if it is a sealant but I have never used it.

----------


## Timber21

Thanks Cyclic... 
there is currently 60mm clearance under the downpie 
Note: photo above
I thought about shortening the downpipe but there would be a problem with fixing it. At the moment it is fixed right on the bottom edge. Shortening it would require fixing to the cement sheet and thereby risking further damage down the track.
I think I may try bonding some flashing to the downpipe with some of the Sika. 
Just as some feedback for you...I spoke to a Tech Support person at Sika regarding the 2 products. He agreed with you...the FC is a more suitable product because the cure time is only a couple of days whereby the PRO requires about 6 weeks full cure time. He said for my purpose, definitely go with the FC.

----------


## Timber21

Update:
I installed the flashing, coated the new decorative timbers with Crommelin Exterior Grade Waterproofing before re-attaching. I then sealed the gaps with a Selleys exterior grade sealant and gave the final coats of paint. 
On the advice of a roof plumber, I re-attached the original downpipe without any alterations.
While the caulking job is not exactly "neat', it seems effective and watertight. It cannot be seen from ground level so not too perturbed. Now just waiting for a little rain to test it all out  :Roll Eyes (Sarcastic):

----------

