How to renovate a damaged weathered timber deck?

[Abe70]

Our 20 year old tongue and groove hardwood (veranda covered) timber deck was/is showing minor signs of rotting on the end grain of the timbers. I have filled and painted 100mm of the end of the boards which seems satisfactory for light rain. Unfortunately the decking has been laid the wrong way with the end grain of the planks exposed to the weather. The timber has shrunk, the previous tight tongue and groove joints have opened up and during windy rainy exposures the rain can wet up to 1 metre of the wood and then drain back into the channels between the planks and deteriorate from behind the  water based filler that I have used. Maybe a deck sand followed by multiple coats of a marine grade epoxy to fill up and seal the gaps between the boards?

[KatieC]

Hi @Abe70,

Welcome to the Bunnings Workshop community! It is great to have you join us and ask about restoring your deck. Our resident DIY guru @EricL will be online later this afternoon, but let me suggest you check out this article How to renovate a timber deck in the meantime. 

You'll find Workshop to be a great source of inspiration and advice for all things DIY and garden. Let me know if you need any assistance with Workshop, I am happy to help.

Katie

[EricL]

Hello @Abe70

Allow me to welcome you as well to the Bunnings Workshop community. Thanks for sharing your question about repairing your weathered timber deck. Would there be any chance of posting a photo of the deck's current damage? This will give our members a chance to assess its condition. We can then make recommendations on how to repair it.

Once we see the photo, we should be able to tell if the timber deck can still be repaired or will need to be replaced.

We look forward to seeing your photos.

Eric

[Abe70]

Hi Eric,

          thankyou for your prompt reply, I have enclosed 2 images (1 showing the extent of rain wetting, the other the worst affected joint) Regards AbeExtent of rain wettingWorst of affected joints

[EricL]

Hello @Abe70

Thank you for posting photos of your deck. The damage does not appear to be too severe and I agree with your proposed course of action. But before you begin, I suggest scheduling the repair when there will be no rain for at least a week. If you have access to an electric sander it will make the job go quicker and easier. However, if not make sure to use a sanding block to get a uniform finish on the boards.

Once you've sanded the panels down, I suggest going with your preferred brand of marine grade epoxy in conjunction with Bondall Marine Grade Varnish. However, if you prefer a different sealer, please make sure that it is rated for exterior use.

Let me call on our experienced members @TheRenoDad and @Adam_W for their recommendations.

If you need further assistance, please let us know.

Eric

[TheRenoDad]

Hi @Abe70 !

Thanks for the tag @EricL , happy to assist.

This is interesting as tongue and groove is not suitable for exterior applications even undercover.

Decking requires a gap of at least 5mm between planks in order for the water to run off.

My recommendation would be to remove what's currently there and replace it with new decking.

This will mitigate the risk of further timber and frame rotting due to water log.

The cheaper option is 90 mm pine decking  or you could go for a darker wide hardwood such as Select Merbau Decking 

Reach out to the community if you need any further help.

Cheers!

Luke | @TheRenoDad 

[EricL]

Hi @TheRenoDad

Thanks for offering that alternative. Tongue and groove are difficult to repair once water damage gets trapped between the timber pieces.

Eric

[Abe70]

Hi TheRenoDad,

                        thankyou also for your prompt reply, I agree Merbau decking would be the best solution however for heritage reasons and replacement cost (125 sqm) at this stage I will persist with the t & g.                                                                                                                                                                          Thanks Abe                 

[TheRenoDad]

Thanks @EricL 

I agree that’s it’s an alternative and it’s possible to repair the tongue and groove to a certain extent, plus may be a good cost saver in the meantime.

Each to their own of course 😊

[TheRenoDad · Accepted solution]

Fair enough @Abe70 

A good sand and a quality stain as @EricL suggested will definitely get some more life out of it.

Plus can totally understand that replacing 125sqm of decking in a heritage situation is a huge undertaking.

Cheers,

Luke