Couple of questions for spec'ing a "lean-to" garag

[pmx_super]

I'm looking to get some quotes to have some work done on my nearly falling down garage. It's adjacent to the house and so shares a wall with the house. I like to feel a little bit informed going into these conversations so have a couple of Qs:

1) How should they be securing the roof joists to the side of the house? At present there are only 3. 2 are stuck into holes in the brickwork and are sliding out (!), 1 is resting on a wooden block that's bolted all the way through the wall with a nut on the end (fortunately in the downstairs toilet).
2) I want the frontage to blend with the house. My house has very pale mortar (almost looks white from a distance against the brown brick). Is there something specific I should be asking for to get a match (e.g. lime mortar)? I predict being fobbed off.. "oh nobody uses that anymore".

 

[^woody^]

A timber bearer plate bolted to the wall, and the new joists either fitted on top of this or to the side of this off hangers

The mortar can be matched with either a light sand, some lime in the mix, or some white cement.

 

[pmx_super]

Thanks Woody. If the joists sit on top of the bearer plate what prevents them from moving? Should they be screwed down to it somehow?

 

[^woody^]

The rafters are notched, so they sit flat on the plate, and then spiked with some nails, or a plate or truss bracket can be used

 

[pmx_super]

Got it thanks. Completely new question, same subject.

I've noticed that a few of my neighbours have a second skin of blockwork inside the outer brick wall (i.e. not the main house wall). Probably sounds dumb, but that lead me to wonder if I should have one too.

The only benefit I can think of is the thermal insualtion of having a cavity - would a cavity alone be significant in this regard? Also the existing brick wall is supported by 3 pillars along its length (1 brick width deep). Would the block skin touch these pillars or would I have to leave a gap? I understand block work is lighter than brick - would it be ok built onto the concrete floor of the garage or would it require additional foundations?

 

[noseall]

There is little to gain by adding another skin to a garage unless you plan on converting this space in the future.

There may be argument to suggest that a single skin wall has a greater potential to suffer penetrating damp from say driven rain. This is only likely to happen on an exposed wall and only then in severe persistent conditions. Maybe once every 5 years.

However if you are likely to be using the garage for something other than storing a car or other stuff, i.e. a workshop, or if you intend spending many hours in there, then you may need to consider whether it is really a garage you intend building.

 

[^woody^]

A new inner leaf might need a new foundation, so increases the work and cost. So unless there is a specific need, should be avoided

 

[pmx_super]

Thanks for the comprehensive and informative replies.

Brick wall is about as sheltered as imaginable (it's about 3" from the corresponding wall to my neighbour's garage along its whole length). Garage is to be used as a gym. I'm planning on using an electric heater in the extremes of winter so want it to have some degree of insulation.

 

[Deluks]

You can build an insulated timber stud wall, finished off with plasterboard, without needing new foundations.