new extension

[grays85]

Hi all.. we're moving along swimmingly.. i have a slight question though. We are having a sunroom to the rear of our property and will be accesable from the lounge and kitchen, all being open plan. We are using the old bricks created from making the new openings from the kitchen and lounge for the exterior brickwork, using lime mortar to match the rest of the property. the question is that we are using concrete blocks for the internal walls, which we have been told to plasterboard, if the idea of lime mortar is for the wall the "breathe" what will happen if we use concrete blocks and cement mortar or do the blocks have to be bedded on lime? can you advise, or do we bed the blocks on lime and then lime plaster the blocks>> confused :shock:

thanks all in anticipation

 

[biffvernon]

>do we bed the blocks on lime and then lime plaster the blocks?

I would.

 

[Penners]

Biff - would you use lime mortar for the concrete blocks because it's of benefit to the building, or simply to reduce the planet's output of OPC?

 

[biffvernon]

Both.

Whether the 'masonry' is stone, brick, concrete, logs or old wine bottles, the advantages of lime pertain.

 

[Penners]

old wine bottles

I wonder how many houses I could have built, if I'd refrained from my visits to the bottle bank?

 

[grays85]

thanks Biff... i/ we have been told by building regs that we need a DPC for the "new bit" so, the moisture wont rise up in to the blocks and disipate out into the room and continue the moisture cylce, however i assume the moisture cycle will prevail coming through the outside wall, throught the blockwork and ultimately through the lime plaster.. all will be well then?

 

[Penners]

If you're constructing the new bit with a cavity wall, you should incorporate a dpc in both "leaves" of the wall.

There should be no moisture penetration into the interior of the new part of the building. The dpc prevents it from entering from below, and the outer leaf of the cavity wall prevents the inner leaf from getting damp.