How do I waterproof and repair a rusted shed?

[DanniU]

Hi,

I am currently in the process of sealing my shed to convert into a home office area.  While going through the process I have seen how bad some of the areas are.  I have a few questions if anyone is able to help.

I was planning on sealing with an outdoor UV resistant sealant and expanding foam on the inside, similar to other areas higher up the walls.

The large gap areas, should I instead be installing some sort of L bend piece of metal, attaching to the inside of the wall and then sealing the smaller gap?  What is a suggested item to use for this if so?

With the outside being concreted with poor sloping and no gutter above, what's the suggested fix?  Should I be installing some sort of drainage?  What is the suggested way forward for that?

Thanks for your help!

[EricL]

Hello @DanniU 

Welcome to the Bunnings Workshop community. it's sensational to have you join us, and thanks for sharing your question about your shed.

I suggest having a quick look at this guide and discussion - How to waterproof a shed floor and Solved: How to install flashing to seal shed and vermin proof by @Rona. Your idea of adding an aluminium angle is the suggested method of stopping water from coming into the shed. I would suggest cleaning the edge of the shed very well with a pressure washer to remove all the dirt and debris that is on the concrete base of the shed. 

Once the concrete base is dry you can attach an aluminium angle to concrete floor and get it as close as you can to the shed wall. You can then fill the gap with Sika 300ml Grey Sikaflex 11FC Plus Polyurethane Adhesive Sealant. Since your shed does not have the usual "U" channel you'll need to install another aluminium angle inside just to make sure that you won't get any water ingress. Please do not use self-expanding foam as this is not an effective sealer.     

Installing a drainage might be necessary if the deluge of rainwater in the area is quite strong. installing a gutter to the shed will definitely help in diverting the water that is coming down from the shed roof. Can you please post a photo of the shed roof? This will help us understand what wind of roof shed you have; we can then make recommendations on how to attach a gutter to the shed. 

If you have any other questions we can help with, please let us know.

Eric

[DanniU]

Thanks @EricL 

Those were great resources.  I went and looked at the profile of my wall and there would be significant gaps between the added aluminium angle and the wall.

Is there a particular product I could use instead that allows me to more easily match the profile of the wall?  Could I use flashing or flashing tape + sealant?

[EricL]

Hello @DanniU 

It is possible to use CAgroup 100mm x 10m Weatherproof Byute Flash Flashing Tape. You'll need to use a Trojan 8oz 225g Fibreglass Soft Face Hammer in combination with screwdrivers with round ended handles to form and mould the flashing tape into the shape of the wall. I still recommend using the Sika 300ml Grey Sikaflex 11FC Plus Polyurethane Adhesive Sealant along with Zenith 12G x 20mm Galvanised Hex Head Metal Screws - 50 Pack to hold the flashing in place. 

My best advice is to clean the bottom surface of the shed to remove all the mould, rust and mildew that may have formed on it. In this manner you'll get a good positive seal when apply flashing on the surface.

If you need further assistance, please let us know.

Eric

[DanniU]

Excellent, thank you for your help!