New build mouldy garage

[Hytheroad]

Hi all, we just moved into our new build house in October. We have found within weeks that we can’t keep things in the garage. Boxes are becoming soggy and falling apart and our sons baby car seat is covered in mould. Builders say we can’t expect it to be water tight... but surely this can’t be right? The garage is built into a dip so it had earth spring the sides, but we can see a damp proofing plastic quite high up the walls. But there are no air bricks... not sure it matters in a single brick construction. Has any one has this issue or have any advice? Thanks

Sounds like something is wrong. We had a wooden shed once upon a time and stuff remained dry in there, although sliders frequented it regularly.

I wonder if it lacks ventilation? If you have boxes raised off the floor do they still get wet?

" it had earth spring the sides, "

what?

Yes they do still get wet. I was thinking the same. We have had sheds we are dryer!! So frustrating!

Is it brand brand new build OP? That's not right at all if it is.

Our new build garage was damp too. It’s the single skin. Water penetrates through the bricks.

We had to store stuff in sealed plastic boxes

Sorry it had earth built up the sides and back. Which has a damp proof course around it to protect against the soil. But still very damp!

Thanks. I know they aren’t water proof as such. But I can’t understand how in a matter of weeks things are going mouldy.

start by increasing ventilation. Even wiithout earth heaped on the walls, you will get drying-out damp and rain making the inside humid, and, being poorly insulated, condensation will form every day on the materials that got cold overnight.

Is there a personal door or a window? Or just the vehicle door?

Start by putting your stuff in plastic storage crates with tightly-sealed lids. They can be stacked so do not use a large size that you will be unable to lift off and on the stack wgen full.

Put nothing directly on the floor. Pallets will do for a short time as spacers but will quickly rot if damp.

Do identify where the lamp is entering, put some pieces of clear plastic on the floor and the walls. In damp is entering through that floor or wall, water droplets will form on he flooe or wall surface. If it is condensation, it will form on the room side.

Do you have electricity in the garage?

is it alone or in a block?

Observe the roof, gutters and downpipes for signs of water leaks.

Observe if water or earth can fall or stand on the exposed concrete slab if it projects beyond the building walls.

To be fair to the builder, the building regs for unheated non habitable rooms such as garages is just that the structure won't be damaged by any moisture.
Even your house would get damp if left un heated in winter.
But in reality you can reduce the ground levels and also add some background heating or dehumidification.
Another option is to turn it into a proper room to building regs and add it to the main heating system, although that's a lot more expensive than plastic boxes and a dehumidifier!

Thanks that’s really helpful. It is stand alone and has electricity.

Also just the garage doors - two as it’s a double with no dividing wall.