How to stop water coming into my sunroom?

[RayZ]

Hi brain trust,

Long time luker first time poster here!

I have a couple of questions about water seeping in sunroom now damaging the skirting board inside. 

Let me start with the background first. 

The sunroom is built on a concrete base converted from a pergola. I am 99% sure the sunroom was a DIY job by the previous owner as the workmanship is not great. The house was built in 2004 and the sunroom is only 3-5 year old according to the agent (we just moved in a couple of weeks ago and noticed the water damage definitely has been there for a while).

Problem 1: Water seeping in damaging the skirting board. Yesterday I used some masking tape to seal the cracked silicone and grout outside to prevent from the heavy storm, water is still coming in, when I touch the gap between the skirting board and tile in side, my finger gets wet (not just moist). I am not sure if I can just use silicone to seal outside and re grout outside (see the concrete cracks and missing grout in the pic1), or should I also use something to seal the whole white MDF panel under the glass? The exterior white paint is a bit bubbling during rain.

A couple of tiles inside near the damage feel hollow too, but I am not sure it is water damage or just bad workmanship. 

Problem 2, the sliding door is dodge. The frame sill is not completely aluminum, there is a long timber in between along the whole the sill, it gets wet and a little bit sponge so I also used a masking tape to cover it as a super temporary measure.  See pic 4, the circled in green section is the masking tap masking the brown timer underneath.

I am reasonably handy, recently replaced whole bathroom basin, a few roof tiles, sand and paint furniture etc but dont know anything about this kind of problems. Any help will be much much appreciated. Budget is really tight after purchasing this house so I need to learn how to fix it myself.

I have also read this post but my problem is more than just sealing sliding door frame hence asking. 

https://www.workshop.bunnings.com.au/t5/Whole-of-House/How-to-stop-water-seeping-in-sunroom/m-p/2961... 

[MitchellMc]

Welcome to the Bunnings Workshop community @RayZ. It's terrific to have you join us, and many thanks for your question about preventing water ingress.

It sounds like you’re dealing with a fairly significant leak, and given what you’ve described and shown, this really does need a professional assessment. There’s quite a bit of water getting in, and with how those sunrooms are usually built, there are multiple potential points of entry that would make it very difficult to track down and fix with a simple DIY approach. The priority is to determine exactly where the water is getting into the frame and wall, as the issue could be coming from the join between the slab and the wall under the windows, or even through the window tracks themselves. The silicone that’s already been added along the tracks suggests this has been a problem for a while.

Because of the amount of water, it’s likely that there’s damage behind the interior panels, so I’d suggest removing the skirting and the internal wall cladding under the windows to inspect what’s going on behind. That will give you a clearer picture of how much of the timber framework has been affected. If the framing is wet or rotted, those timbers will need to be replaced before any sealing can be effective. Once you’ve opened up that area, it should also help you trace back to where the water is entering outside.

Unfortunately, with many DIY sunroom or patio enclosures, proper weatherproofing and flashing aren’t installed, which leaves them vulnerable to the sort of leaks you’re seeing. At minimum, I’d recommend some exploratory work inside to assess the extent of the damage and then consider bringing in a moisture detection specialist or building inspector to identify the source. From there, you can plan the repair confidently rather than sealing blindly from the outside, which rarely solves the problem long-term.

Please let me know if you have any questions.

Mitchell
 

[RayZ]

Thank you so much @MitchellMc for such a swift and detailed response. I agree this is complicated I guess I will get a builder to inspect and see what the options are. Ripping off and rebuilding is not really an option at this moment due to budget constrain hopefully can be repaired well enough to last at  least 5 years. 

[MitchellMc]

Hopefully, rebuilding is not necessary, but I think, at a minimum, removing the internal lining of the bottom wall will help reveal the penetration location, @RayZ.

Mitchell