Sealant for concrete garage?

[Rrobson]

As the title suggests my prefab garage (of quite a few years, at least 20) leaks water between the panels and the floor along a portion of the back wall. Is there a sealant that will adhere to the panels and the concrete floor to prevent some of this coming in? There’s nothing to damage really but it’d be nice to have less coming in.
Thanks

 

[brightspark]

tec 7 it will stick to wet substrates and concrete no probs just gun it in with a sealant gun

 

[123hotchef]

are there gaps? or is it just pourous?

 

[123hotchef]

tec 7 it will stick to wet substrates and concrete no probs just gun it in with a sealant gun

or CT1

 

[Rrobson]

are there gaps? or is it just pourous?

I’m assuming there’s a small gap, and water settling on the pad outside is wicking in. Only along the one edge though and it’s probably two panels that’s having the problem but I’d like to do it all to future proof it a little.
I’ll be redoing the roof this year, probably in epdm because I’m fed up with covering everything in plastic sheeting to keep it dry, although that isn’t causing the wetness at the back, just in other places…

 

[voipio]

Does the water pool on the concrete outside the panels?

 

[Rrobson]

Not really, it’s pretty level and it’s only overhanging the exterior of the garage 5” or so, but the roof slopes to the rear. I’d imagine if there was a gutter here it would stop most of the water ingress and it’s part of the re-roof I’ll be doing. Most of the leaks are related to heavier downpours but obviously looking for temporary fixes until I properly sort it.

 

[gaz1]

6x2 panels ?

or another sort

if your gonna reroof it why dont you jack it up by 2" if you can do
by fitting 3x2s or 4x2s on top of the original metals it will also give you something to fasten the side woods too for your edges either side of the garage

 

[Rrobson]

I was planning on doing that
I also thought about putting an insulated roof on but figured I’d be wasting my time with the walls being uninsulated. Would be nice not to have to wipe the condensation off the lathe on a cold morning…

 

[gaz1]

its worth doing for 2" or 4" insulation with 2" below the woods

but as your roofing it with boards id jack it up and insert insulation in as well

Another roofing question.

keep it simple and build the frame up barge board it and fit everything on it then fill with insulation built the same way just not with large gaps

www.mig-welding.co.uk

have you got a 8ft wide or a 10ft wide as you can either do full lengths down the roof and fit insulation boards inbetween or fit across the steel cross section and fit insulation between the cross members

if you do length woods down your garage then you can fit insulation inbetween you can fasten to your woods from underneath giving you a full 4" of insulation that also bridges the cold of the woods

also easier to board as well

just remember if you do jack it you will be raising the roof 3" in total
2" insulation and 18mm boards
if not use 1" insulation and 2" underneath

 

[qwakers]

why dont you just render the out side. doesn't cost much to do, isn't difficult to do a passable job and will perfectly waterproof it whilst making it look a lot nicer.

 

[Rrobson]

It’s 10’ x 20’ and there’s a place local selling 10’x4’ osb to make life easy. Sounds promising I didn’t think there’d be a noticeable difference so thanks for that. Will look into it.

@qwakers I’ve only got access to the door and one side because there’s a shed behind and 10” gap along the other side due to neighbours garage…

 

[qwakers]

so render the inside. less ideal but almost as effective. or even better, batten off for a airgap and insulate.

 

[gaz1]

i have both a brick shed and a garage shed there is a noticable difference in there when your using it

the insulation does make it more bearable

ive used bubble insulation on the internals as its cheap and easy to replace its just bloody reflective but i know my shed is newly sealed so wont make a difference

 

[500e]

Have single brick garage/wshop at home painted them with silicone stopped all damp through the bricks, floor to brick was sealed when built never been a problem has 120mm foam under the pad.

 

[bricol]

Prefab garages tend to move a bit - so solid render, inside or out, cracks - and lets water in behind.

I applied a good thick bead of builders silicon, bought by the case, down all joints when I put my double up. I applied the recommended cement fillet inside . . . it cracked . . . Couple of years ago, i chiseled it up, used a grinder to clean out a touch under the panels, inside and out, gave it all a serious wire-brushing followed by blowing out all the dust and applied polyurethane sealant, worked in the slit under the panel edges, good fillet inside.

Theory being it'll flex a touch as the panels move a bit. So far, seems to be working - especially the last month or two - seems it only stops raining to rain harder!

 

[gaz1]

silicone isnt the best thing to use its ok for a while until the movement of things gets too much

the likes of pvc windows and baths prove this point really well

they fail over time due to expansion and contraction of the materials they connect too or the surface goes powdery like stone does

you need to use mastic sealant that dosnt set

 

[Gareth J]

Can you change the outside concrete so it slopes away?

Can you cut a slit in the concrete and tuck in a length of dpc up against the outside of the garage with a decent fillet of stron concrete? A bodge, but might help

 

[bricol]

silicone isnt the best thing to use its ok for a while until the movement of things gets too much

the likes of pvc windows and baths prove this point really well

they fail over time due to expansion and contraction of the materials they connect too or the surface goes powdery like stone does

you need to use mastic sealant that dosnt set

My experience of mastic sealant is it goes hard, and falls out. 20 yrs of silicone applied to dry, as dust free as it can be got, concrete reveals it works very very well.