Ideas please for my Motorhome garage.

[Tombola]

CazPaul

this maybe of interest

My garage build

After years of umming and ahhing about whether or not to build a garage/workshop we’ve finally bit the bullet and decided to give our motorhome an easy life and keep her out of the scottish weather. Building will be in two parts......a garage for motor home (5m x 8.5m) and second part a smaller...

www.motorhomefun.co.uk

 

[Ivory55]

Would the land drain have to be below the first course of blocks, or all the water would collect where the straight joint is with the concrete and it could seep in , just thinking again.

 

[bobnick]

Not read all the above posts so apologies it i am repeating any.
That membrane should be at least 2000 gauge..is it. Ensure garage floor has 2000 gauge before concreting.
When you back fill behind the block back fill with aggregate or similar, it aids draining water away. A land drain around the perimeter before back fill would benefit.
Ideally the block externally should have at least a waterproof paint.

 

[jongood]

I am assuming the floor level is top of blockwork. ?
So, you have concrete floor, on membrane, thicker the better (2000 gauge). on 25 to 50 mm sand blinding on 150 mm of consolidated hardcore, on the ground you have.
The membrane passes under the concrete, turns up the sides between the concrete and wall, turns onto the top of wall and is trapped with a course of bricks or blocks. This can also trap the one you have externally
The membrane is kept in place by the concrete, which as said I assume is the same height as your blocks.

This is what I would do - Imagine a Z Paul just leave your DPM long at the back lay the blocks on it, go up as many course as you need to get you at least 150mm above ground and then bring it back over (just to fasten it really), you might have to think how to finish it outside though., are you going all the way up in brick/block or are you going to timber?

The knack of making something good is to imagine what you re going to be looking at at the end, doesnt always work but usually better if it looks decent.

 

[jongood]

Don't forget to wrap your land drain in permeable membrane

^{_{Subscribers  do not see these advertisements}}

 

[CazPaul]

So the builder wants to do as Minxy Girl suggested and the floor dpc membrane under the concrete wrap up all the way up the internal walls to ground level. I said ok but im not sure what do people think Landy Andy and others.
He says best way to get a watertight seal, then cover in thin wood planks or something.

Problem is i want to know if the internal walls are damp and is it just covering a multitude of sins?

There is enough room at the rear to get another wall with a small cavity which i am pleased about.

 

[Landy Andy]

What he wants to do will work, but I wouldn’t want to have black plastic up my walls. As soon as it gets a hole in it it stops working, it looks horrible and how are you supposed to cover it if you can’t fix through it. I would always try as hard as possible to keep the blocks dry from the exterior. Either by bitumen paint, or membrane.
The only down side I can see of doing either of those is money/time. But I know by experience a damp garage is a complete PITA. I’m try to come up with plans for my damp garage, and am struggling without knocking it down and starting again, I wish the builder/home owner at the time had put more effort into the build.

 

[Tombola]

What he wants to do will work, but I wouldn’t want to have black plastic up my walls. As soon as it gets a hole in it it stops working, it looks horrible and how are you supposed to cover it if you can’t fix through it. I would always try as hard as possible to keep the blocks dry from the exterior. Either by bitumen paint, or membrane.
The only down side I can see of doing either of those is money/time. But I know by experience a damp garage is a complete PITA. I’m try to come up with plans for my damp garage, and am struggling without knocking it down and starting again, I wish the builder/home owner at the time had put more effort into the build.

my brother in law keeps his beloved honda vtx 1300 in the garage that is damp and says there are literally small puddles sometimes, hes constantly taking small rust areas off his chrome. I told hime abut making sure there is plenty ventilarion but he says there is ????

 

[Landy Andy]

I know how he feels. I’m now running a dehumidifier 24/7 in mine to stop the water damage to my stuff. I’m getting condensation dripping down, and water appears through the back wall of mine creating puddles at the back of the garage. I’ve racked it with metal shelving to keep everything off the floor, and away from the walls, but its still a problem. Not ideal with a good few thousand ponds of tools, and a couple of very expensive E bikes. Annoyingly it would have been cheap and easy to avoid when it was built.

 

[Minxy]

So the builder wants to do as Minxy Girl suggested and the floor dpc membrane under the concrete wrap up all the way up the internal walls to ground level. I said ok but im not sure what do people think Landy Andy and others.
He says best way to get a watertight seal, then cover in thin wood planks or something.

Problem is i want to know if the internal walls are damp and is it just covering a multitude of sins?

There is enough room at the rear to get another wall with a small cavity which i am pleased about.

It really depends on how 'good' a watertight garage you want.

The lower external walls will be damp but that's normal as anything below a damp proof course will be, their being damp won't be an issue IMV - think of them as 'footings' rather than walls.

^{_{Subscribers  do not see these advertisements}}

 

[Minxy]

What he wants to do will work, but I wouldn’t want to have black plastic up my walls. As soon as it gets a hole in it it stops working, it looks horrible and how are you supposed to cover it if you can’t fix through it. I would always try as hard as possible to keep the blocks dry from the exterior. Either by bitumen paint, or membrane.
The only down side I can see of doing either of those is money/time. But I know by experience a damp garage is a complete PITA. I’m try to come up with plans for my damp garage, and am struggling without knocking it down and starting again, I wish the builder/home owner at the time had put more effort into the build.

Read my suggestion as to how to sort that. There's nothing to stop the OP coating the outside blocks with a waterproof treatment/coating of some sort too.

 

[Minxy]

my brother in law keeps his beloved honda vtx 1300 in the garage that is damp and says there are literally small puddles sometimes, hes constantly taking small rust areas off his chrome. I told hime abut making sure there is plenty ventilarion but he says there is ????

Does he heat it to try to offset the damp? If so it could be causing condensation.

 

[Minxy]

I know how he feels. I’m now running a dehumidifier 24/7 in mine to stop the water damage to my stuff. I’m getting condensation dripping down, and water appears through the back wall of mine creating puddles at the back of the garage. I’ve racked it with metal shelving to keep everything off the floor, and away from the walls, but its still a problem. Not ideal with a good few thousand ponds of tools, and a couple of very expensive E bikes. Annoyingly it would have been cheap and easy to avoid when it was built.

What is the construction material of yours? We have prefab garages and whilst we get some damp we also get some dripping at the very rear but we found out part of the problem was that some moss had grown on the roof and was blocking the channels in the corrugated roofing sheets so it was forming pools and eventually seeping in between the sheet edges.

 

[CazPaul]

What he wants to do will work, but I wouldn’t want to have black plastic up my walls. As soon as it gets a hole in it it stops working, it looks horrible and how are you supposed to cover it if you can’t fix through it. I would always try as hard as possible to keep the blocks dry from the exterior. Either by bitumen paint, or membrane.
The only down side I can see of doing either of those is money/time. But I know by experience a damp garage is a complete PITA. I’m try to come up with plans for my damp garage, and am struggling without knocking it down and starting again, I wish the builder/home owner at the time had put more effort into the build.

I agree but now he has done most of the walls to ground level so now how else would you do the floor dpc if not going up the walls

Would tacking it to the wall 6 inch up work?

 

[Landy Andy]

I would cast the floor in it’s own plastic liner, then cut it off at the top once it’s set.

What are your plans for the internal walls of the timber section?

^{_{Subscribers  do not see these advertisements}}

 

[Ivory55]

Is there any water proof chemical that could be added to the concrete mix to help with any damp coming up ? This is me thinking again, haha.

 

[bobnick]

Is there any water proof chemical that could be added to the concrete mix to help with any damp coming up ? This is me thinking again, haha.

In fact yes there is.

 

[Tombola]

Does he heat it to try to offset the damp? If so it could be causing condensation.

no its not even his garage its his neighbours whose house is empty and lets him leave it in there.
ive stopped listening to him going on about it tbh , Id have my own little bike shed if I was him

 

[CazPaul]

I would cast the floor in it’s own plastic liner, then cut it off at the top once it’s set.

What are your plans for the internal walls of the timber section?

Yes hes setting it in plastic he said then cutting off because I told him I didnt want all the blockwork covered in plastic.

Not sure about the timber walls, would like to insulate them and the roof but would it stop the timber from breathing?

 

[jongood]

So the builder wants to do as Minxy Girl suggested and the floor dpc membrane under the concrete wrap up all the way up the internal walls to ground level. I said ok but im not sure what do people think Landy Andy and others.
He says best way to get a watertight seal, then cover in thin wood planks or something.

Problem is i want to know if the internal walls are damp and is it just covering a multitude of sins?

There is enough room at the rear to get another wall with a small cavity which i am pleased about.

Tbf he is the man on site. Is he doing it that way because he thinks it will be better for you or easier/cheaper?

^{_{Subscribers  do not see these advertisements}}

 

[CazPaul]

Tbf he is the man on site. Is he doing it that way because he thinks it will be better for you or easier/cheaper?

He is not doing that way now I didn’t want plastic dpc covering all the interior concrete blocks.
I think if the inner blocks get damp you want to know instead of having them covered, they need some airflow for any moisture to wick away.
I am going to paint some of that tank slurry on the outside of them before he back fills it. That will be a few weeks yet he should be finished all the block work today if he has enough blocks.

 

[Minxy]

Yes hes setting it in plastic he said then cutting off because I told him I didnt want all the blockwork covered in plastic.

Not sure about the timber walls, would like to insulate them and the roof but would it stop the timber from breathing?

So what's going to stop the damp coming in through the blocks then?

 

[Minxy]

He is not doing that way now I didn’t want plastic dpc covering all the interior concrete blocks.
I think if the inner blocks get damp you want to know instead of having them covered, they need some airflow for any moisture to wick away.
I am going to paint some of that tank slurry on the outside of them before he back fills it. That will be a few weeks yet he should be finished all the block work today if he has enough blocks.

Why? They are in effect 'tall footings' which you wouldn't normally see ... all that's gonna happen is that it will introduced damp into your garage.

I'm outta this thread I think as it's winding me up.

 

[jongood]

So what's going to stop the damp coming in through the blocks then?

Good question, the paint stuff is good but I wouldn't want to rely on just that

 

[jongood]

Is there room to put land drain around the outside?
Btw I wouldn't put a surface drain in side because of pollution risk.

^{_{Subscribers  do not see these advertisements}}

 

[CazPaul]

Why? They are in effect 'tall footings' which you wouldn't normally see ... all that's gonna happen is that it will introduced damp into your garage.

I'm outta this thread I think as it's winding me up.

Lol there’s no need to be like that, it’s all opinions thanks to everyone who has contributed here.

 

[jongood]

Lol there’s no need to be like that, it’s all opinions thanks to everyone who has contributed here.

You're right Paul she Minxy Girl needs to get out more not long now.

 

[CazPaul]

Is there room to put land drain around the outside?
Btw I wouldn't put a surface drain in side because of pollution risk.

I want to put a dek drain right down both sides right the way to the bottom, builder says not necessary he wants to put a land drain higher up just below the gravel infill on one side only.

Will the moisture/water bypass the higher land drain and track to the bottom?

 

[jongood]

I want to put a dek drain right down both sides right the way to the bottom, builder says not necessary he wants to put a land drain higher up just below the gravel infill on one side only.

Will the moisture/water bypass the higher land drain and track to the bottom?

Water usually flows downhill mate

 

[Minxy]

Lol there’s no need to be like that, it’s all opinions thanks to everyone who has contributed here.

Its quite frustrating for those of us who are trying to ensure your garage doesn't get damp when what you are proposing is still gonna allow damp in, you really don't want that to happen, trust me, you don't, it's not just about the walls being damp but everything inside will suffer too.

If you are really, really against having anything covering the inside of the blocks then you need to do something outside instead to prevent damp coming in permanently, its either membrane inside or outside, but it needs it in one of the places.

Personally I'd rather have it inside, stuck in place with a waterproof adhesive, and then covered, maybe some sort of rubberise flooring material placed on the wall would look better but also ensure that when opening the car door etc it wouldn't get 'chipped' on the wall?

I fear if you don't do this then in future you're gonna have to do something to stop the damp anyway, so better to get it resolved once and for all now.

^{_{Subscribers  do not see these advertisements}}