Any Brick Experts in the Crowd - My Morter is Crumbling

[Tidybuoy]

I was wondering if anyone would know what the cause & cure is for my crumbling morter problem.

The front of my house is brick - built 1949. The bricks under the windows has morter crumbling and it is getting worse each year.

I figure I need to pipe in morter but I'm wondering if I need to remove the existing morter first. I'm also wondering what is the cause. It seems to only be happening at the base of two large picture windows but nowhere else on the house.

Here's a photo of the problem:

[Rot 911]

Mortar just gets old and starts to crumble. Quicker where it is more exposed to the weather. My guess on yours is that being at the base of the windows the mortar sees a lot of rain run off. You need to grind out the old stuff and tuck point in with new. I use a 4" angle grinder. Just google "tuckpointing mortar" and you will find lots of "how to" posts. Fairly inexpensive, but labor intensive and messy job.

[dad911]

Test other areas and see if you can shove a screwdriver/awl into it.

Scrape out the bad areas and re-point.

Sealing it may extend the life, but hey, 61 years ain't bad.

I wonder if there is asbestos or anything else nasty in the old mortar. I would probably wet & scrape it out instead of attacking it with a grinder and making alot of dust.

[gr8fl4porsche]

Standard problem.

As stated above, it's related to water. Water runs off house and windows, starts to erode the mortar (and bricks). Small holes and cracks start to develop which accelerates erosion.

Dig out anything soft and crumbling. You can use a screwdriver or anything that will get between the bricks. Before you tuckpoint, spray the old mortar with a squirt bottle to moisture the existing mortar, this way the old mortar doesn't suck the water out of the new mortar. Do the entire sill - even if some mortar looks good. You can tint the new mortar with dry pigments to gain a closer match.

[Porsche-O-Phile]

Common. Get it tuck pointed. Relatively inexpensive. Modern mortars are stronger and will last longer, typically. Specify a type S or M mortar instead of the type N crap that's typically used in residential.

[Tidybuoy]

Thanks for all the advice. I will look into tuckpointing & get this fixed.

I'm just wondering if I have been doing anything wrong to cause this. As I said, this has only occured at the bottom of the windows. The windosw are not exposed and do not get rain on them as they are on a large front porch. The only think I can think of is that I usually clean them before my annual Christmas party (in the winter and uses water). I do hose down on occasion but I do that to the whole house - the damage is only at the base of the windows.

Thanks......Vern

[looneybin]

it's the high lime content of the older mortars. it turns to powder when exposed to weather.
nothing i can add from the above posts, except maybe some help re-pointing your joints if you need it