The rain is winning

[john d hamilton]

I recently installed a yardmaster metal shed in the garden. After a good shower of rain the inside has huge wet patches on the concrete floor.

The sheds on a cement base with the top three or four inches being a mix of one cement to four sharp sand and under that top layer, it's a mix of one cement to three sharp sand and three Wickes ballast (gravel).

I have put a bead of *clear* silicone around the metal frame base of the shed, but its obviouslly not enough to stop the problem. The Yardmaster technical advice staff have advised using Shell Tixophalte 'seal and fix' flexible bitumen sealer. I cannot get this in any local shops and a web search usually reveals wholesalers who are mainly selling to the trade, and it also looks to be expensive stuff to buy.

This link posted to the tinypic website will show the photo I took of the outside edge of the shed

This picture below is on the inside and shows the metal frame base.

Would anyone advise a novice on; Would lashings of the clear silicone sealant I have already bought be more or less as good to use as a bitumen sealent? I would prefer to use a clear silicone since masses of a black non setting bitumen would not look so good smeared all around the base. but if bitumen is best then i guess i can pick up some at Wickes, rather than use the Shell product?

Another aspect of this wet floor problem is that on the side of the shed (where this photo was taken) the edge of the cement base is only three or four inches from the shed base. But on the opposite two sides the width of the cement base is about 18 inches one side and about 20 inches on the other. My thoughts are, is the cement porous like blotting paper? thus soaking up a lot of water on these larger flat areas and transferring it inside the shed? If the cement base is in fact behaving like this, then i'm guessing i would have to seal the whole width of the base area around the shed.

Since i'm using this outside flat space for storing ladders etc, i would not want to have to walk on a 'non setting' type sealant or i guess even a silicone sealant. If this blotting paper type activity is likely to be 'for real', what might be a way to seal this part of the base please? Grateful for any other advice on this problem, thanks.

[mkirsch1]

You laid down that nice cement pad, perfectly level in every direction and smoother than a baby's butt, right? That's your problem.

A level pad will allow water to collect and pool. The water is pooling on the exposed portion of the pad, then seeping under the wall of the shed. You can caulk and seal until you turn blue in the face, and it won't stop the seepage.

The surface of the exposed portion of the pad should have been sloped AWAY from the shed so that the water that hits it would run off.

Rain gutters to direct the water from the roof of the shed off the pad will help some. Then only the water that falls directly on the pad will pool.

Another option would be to extend the roof of the shed to cover the exposed pad.

You'll never completely stop it.

[HeyBub]

Good catch.

I think that's the way the Egyptians got each concourse of stones on the pyramids level. After each layer of stones, they sealed up the cracks (if any), built a cofferdam, then poured water on the stone blocks. For each bit of stone that stuck up through the water, they rushed over and sanded it down!

Eventually they had the entire stone surface covered with a uniform layer of water 0.1mm thick.