Loose blockwork under car port - subsidence or simply mortar needs replacing??

Hi,

I've got a house and conservatory, built in the 1950's on a slope with a height difference of around 5ft on the lower slope side. The conservatory appears to be built on top of the concrete car port which is adjacent to the house. Breeze block foundations are beneath the house and two structure supporting walls form the car port with a concrete slab on top. (I'm curious to know what their foundations are but it's not possible to tell, because one is a party wall and the other is partly built over with a set of concrete steps leading down from the car port to the back yard.)

Under the car port, near the base of one of the taller supporting wall there are two blocks - possibly breeze blocks but they're painted so I can't tell - which have come loose from the heavy rain which has battered the 'weather' side of the house and washed out the mortar. The wall doesn't appear to be a retaining wall, but rather a wall that simply takes part of the weight of the concrete car port slab and enclose the slope under the car port, possibly to stop moisture getting in.

My question is: is it fairly common for blocks in concrete car port walls to come loose? If I got a builder to re-mortar the blocks am I risking missing a potential subsidence issue that is occurring with the recent heavy rain? And therefore, as a matter of caution, should I instead get a structural engineer in to have a look? The latter seems like overkill...


Thanks

What caused it could be one or more of several things.

By "re mortaring", if you mean repointing that will never strengthen a loose wall. Re laying will. But whether that is the solution to the problem is debatable.

The fact that it has come loose means that it is not taking any weight. Modern mortar does not "wash out" easily , it takes 50 years to do it. So it looks like a bad construction. If this wall is supporting the slab roof then it is definitely load bearing, though not this bit. First have a good look and see that your gutters and down pipes are not directing water onto this area. While you are out there have a good look for any other loose mortar and cracks. This could indicate some larger problem. The is just to prepare yourself for when you get your builder in.
Frank

Woody, yes, re-pointing as you say. Ok, a re-lay would be more reassuring. Hopefully without removing the entire wall.

Frank, yes, makes sense: old conservatory, gutters missing, heavy rain: lots of over-flowing or simply falling off the conservatory roof. I've just had a look and in fact there's a ~4ft long lintel a few block courses above the loose blocks, but a course below the dpm under the conservatory. Not sure why there's a lintel there - maybe an old coal shed that's been bricked up? But then were coal sheds built into 1950's bungalows?? Begs the question, what's behind the lintel - an empty void or filled in with builders rubble... And yes, there's a crack following the line of the brickwork jutting out from the gable end of the house to the conservatory. The mortar is quite sandy and comes out powdery when I rub it with my finger.