Sectional concrete garages

[Sambob15]

Hello

We're looking at getting a new sectional concrete garage but I've come across a lot of references to condensation problems online. Does anyone know whether there's a way of avoiding the condensation, or is it something you just have to put up with if you have this type of garage? I should mention we would have a freezer and condenser tumble dryer in there - not ideal I know but we have a teeny tiny kitchen.

We actually already have a sectional concrete garage, which hasn't had any condensation issues since we bought the house, but that could be because a lot of the sealant from in between the sections has dropped out so it has plenty of unintentional ventilation! It's also got an asbestos roof and some rotten woodwork, which is why we'd like to replace it.

I would love a brick-built garage but unfortunately I don't think our budget will stretch to that.

Thanks in advance for any pearls of wisdom!

 

[John D v2.0]

You'll always get condensation but you can insulate a bit and put some heat in. Even a car standing on the drive can get condensation all over the outside, but the side near the house is often dry because of the shelter and heat

 

[noseall]

Any time you steer a building towards 'habitable' space, whether that be a few domestic white goods, soft furnishings, gym weights etc, there is always the risk of internal moisture causing problems. These spaces are at their most disappointing during the cold winter months.

It all depends on what you want from the building and what you are prepared to put up with. Predicting how it will behave is difficult as condensation related problems are lifestyle dependant.

 

[Harry Bloomfield]

I built mine, originally with an asbestos roof which I have since changed to steel. Taking the car in wet, I would get condensation forming on the roof, particularly when it was cold. Since then I insulated the roof to prevent condensation forming and followed a rule of not putting the in wet, or at least leaving the front and a side door open to allow it to dry off with the through air flow. It has three doors, a remote electric roller shutter door, a small side door, then a larger one into an extension/ workshop I built on the rear end. That also has a metal roof, which I also insulated. I don't think it has anything to do with it being concrete sectional, rather condensation is only a problem of the roof construction.

Mine has a particular issue, that its foundation slab has sunk to soil level over the decades and the sub soil is heavy clay, which means heavy rainfall can flood the garden. Water would then flood the slab with a couple of mm of water, despite adding a web of cement as a dam around the inside of all the sections. It has not flooded for a number of years, since I made a french drain around the edge of the slab, though the winters too have been fairly dry too recently.

 

[Notch7]

How about a new sectional garage, with a section of it separated with a stud wall. Then insulate that section only and put a door on it. Heat it in the winter.

Or build a new garage out of timber if you are diy minded. A properly built timber frame structure would be condensation free. Put 2nd hand upvc door and some windows in.

 

[scbk]

Can you not repair and improve the garage you already have?

 

[ivixor]

A concrete garage is meant to be effectively open to the atmosphere through ventilation and other gaps. It's not a sealed or temperature controlled room.

Providing you keep it ventilated and the inside temperature is the same as the outside temperature, you won't get condensation.

If you actually want a heated room, then you need to build it properly.

 

[Keithmac]

Most Freezers will shut down if ambient temperature gets too low, worth bearing in mind!.

 

[Sambob15]

Hi everyone, thanks for all the replies!

I know it's not great that we have the freezer in there, I wish that wasn't necessary as not only could it make condensation worse but it's not good for the freezer. It's only an old one for spillover food so not the end of the world if it packs up, but I'm hoping it doesn't. Other than that the garage tends to be a store for the usual stuff eg bikes, lawnmower, garden tools. So obviously condensation issues could see all of them gradually turn rusty over the years.

Am I right in thinking that the two solutions for condensation would be to either have plenty of ventilation, or to go to the other extreme and insulate with some additional heating? As I say we have no problems with our current rickety old concrete garage and I can only assume it's because it's got so much ventilation that it matches the outside temperature.

We have considered trying to repair it, but... the concrete base is quite badly cracked, I think because there's a tree right next to it, in clay soil. This obviously can't be fixed but if we were replacing we'd remove the tree and re-do the base. We've the got the rotten timber which would mean the whole window unit needs replacing and possibly some. And even if that was fixed there's the asbestos roof which is from 1960. We just figured adding up the cost and time involved in patching it up, we might be better off replacing it.

 

[Harry Bloomfield]

Hi everyone, thanks for all the replies!

I know it's not great that we have the freezer in there, I wish that wasn't necessary as not only could it make condensation worse but it's not good for the freezer. It's only an old one for spillover food so not the end of the world if it packs up, but I'm hoping it doesn't. Other than that the garage tends to be a store for the usual stuff eg bikes, lawnmower, garden tools. So obviously condensation issues could see all of them gradually turn rusty over the years.

Am I right in thinking that the two solutions for condensation would be to either have plenty of ventilation, or to go to the other extreme and insulate with some additional heating? As I say we have no problems with our current rickety old concrete garage and I can only assume it's because it's got so much ventilation that it matches the outside temperature.

Even with internal matching external, under frosty conditions you will still get ice forming on the underside of the roof, then melting as it warms. I doubt a freezer would make the condensation much worse, unless its insulation has failed. Some fridge/ freezers and freezers are designed to still work in cold environments.

The only way to prevent rust in such a cold moist environment, is to remove the humidity (sealed and a dehumidifier), or spray such items with WD40 each autumn.

You could always dismantle the garage, renew the base and reassemble on the new base. Basic none opening window frames and replacement doors are easy to make for the likes of a garage - I'm no certainly no joiner, but I made up two window frames and two people size doors for mine, plus renewing all of the roof timbers with just basic tools. I also rebuilt the entire front panel to accommodate a new electric roller shutter door, it had originally been fitted with hinged timber doors.

Its a large one - 24 x 12, then ten years ago, I decided I needed more space in the form of a workshop, so I took out two of the rear centre panels, laid a 16 x 10 base and block built a workshop at right angles on the rear, with its own entrance (third), plus entrance via what had been the rear of the garage.

 

[Sambob15]

Thanks, that's food for thought